iPhone Built a calculator that’s actually minimalist and clean.

[aoifh]

📱 App Store → https://apps.apple.com/app/id6745772251

Hi everyone! I'm the developer of this app, and just wanted to share what I’ve been working on.

I’ve always liked simple, clean tools — apps that do one thing well and get out of your way. But weirdly… I couldn’t even find a calculator I enjoyed using.

Most are overloaded with ads, clunky buttons, loud visuals… some don’t even show the full equation.

So I made my own.

✨ What it does
- Full expression view (parentheses & logic included)
- Clean, minimalist layout
- No ads, no gimmicks


🎨 The vibe
I didn’t want something cold or super “techy”.
So I used soft colors, rounded type, and small layout touches to make it feel calm — like a quiet desk tool, not a flashing UI.

It’s minimal, but still human.


📦 What’s next?

This is actually Episode 1 of a little series I’m building — a collection of clean, minimal utility apps designed to feel calm, focused, and consistent.

The next one (Ep 2) is already in the works — and will follow the same vibe: quiet design, simple purpose, no distractions.

If that sounds interesting, I’d love for you to try this one out — and if you have ideas for other “minimal apps” you’d love to see, I’m all ears.

📱 https://apps.apple.com/app/id6745772251
🌐 https://www.minlsm.com

Thanks for reading!

 

[Beards]

£0.99 to download the app….. Then £4.99 for a monthly plan or £29.99 for a yearly plan!!!
What are you smoking?

 

[aoifh]

£0.99 to download the app….. Then £4.99 for a monthly plan or £29.99 for a yearly plan!!!
What are you smoking?

Hey, thanks for checking it out — and I totally get where you’re coming from.

The £0.99 unlock gets you the full core app — clean UI, full equation view, no ads. The Pro plan is just optional, mainly for folks who want history, unlimited entries, and some upcoming features I’m working on. I’m building this solo, so it helps support the updates too.

That said — pricing’s always tricky, and I’m still figuring things out.
Do you have any suggestions on what might feel more fair or make more sense to you?

Really appreciate the honest feedback 🙏

 

[Beards]

Let us just take one Calculator App and do a comparison:-
Solves:Calculator for all - https://apps.apple.com/gb/app/solves-calculator-for-all/id1394359548

1. It has support for all devices i.e. Mac, iPad, iPhone, Apple Watch.

2. It has iCloud support that automatically transfers data inputted in one device to all other devices. That includes any calculation on the Watch is automatically transferred to all devices, ideal if you don’t have your iPhone but need a quick calculation to be stored for a later deep look on any other device.

3. It provides history for all but the Apple Watch.

4. It allows comments for all but the Apple Watch.

5. There are tons of other stuff you can do with Solves+

Now the cost…… £0.00 to download with many of what I have mentioned above FREE.
Upgrade to Solves+ is only £7.00 ~ That is a heck of a bargain

Now we look at what you are offering:-
1. To download costs £0.99 ~ you take a chance that the app will give you something… you have no idea except what you mention but that may still not be enough.

2. You then have to purchase either a monthly or yearly plan ~ Both are exceptionally high.

At this point when you compare the two it is easy to see that Solves & the paid Solves+ are much more attractive.


Answer:- Lower your prices. Download FREE. Delete monthly/yearly subscriptions. Initiate a paid version at a price others will find attractive. Use a support payment method where users can give you further payments if they wish.
Make the app attractive in costs to the user and the user will support.

 

[aoifh]

Really appreciate your detailed feedback — I genuinely value it.

For me, part of what I’m offering isn’t just the features, but also a design philosophy. I know every developer says they care about design — but with minimalism, it’s different.

Even small things like line weight, spacing, or how a color “feels” on screen… they take time and tons of tiny decisions. It’s about creating something that feels clean, balanced, and enjoyable to use — even for something as simple as a calculator.

That said, I hear you on accessibility. I’ve been thinking about how to better share that vision with more people — and maybe free downloads is a way to do that, like you suggested. I’m still figuring it out, and feedback like this really helps.

Thanks again for taking the time — it means a lot.

 

[arw]

- You should take a look at the decimal handling (see screenshot).
- Imho, revealing the history should not require two taps.
- Other apps (like Solves) let you edit the term by tapping at the desired position.
- Do you plan an iPad-optimized version?
Otherwise I like the minimalistic / visual approach.

 

[aoifh]

- You should take a look at the decimal handling (see screenshot).
- Imho, revealing the history should not require two taps.
- Other apps (like Solves) let you edit the term by tapping at the desired position.
- Do you plan an iPad-optimized version?
Otherwise I like the minimalistic / visual approach.

Thanks so much for the support — glad you like the minimal design!

On the first point, just to clarify: do you mean entering 1.1 x 1 gives you 11? Would love to understand exactly what’s going wrong there.

And yes, I agree the history flow isn’t ideal — I’m already working on improving the UX around that.

Tapping to edit a specific part of the expression is a great idea — I’ll definitely consider that for future updates!

As for an iPad-optimized version: it’s not planned just yet, but it’s something I’d love to support once the iPhone version reaches a more complete stage. One step at a time!

Really appreciate the thoughtful feedback. 🙏

 

[hg.wells]

Thanks so much for the support — glad you like the minimal design!

On the first point, just to clarify: do you mean entering 1.1 x 1 gives you 11? Would love to understand exactly what’s going wrong there.

And yes, I agree the history flow isn’t ideal — I’m already working on improving the UX around that.

Tapping to edit a specific part of the expression is a great idea — I’ll definitely consider that for future updates!

As for an iPad-optimized version: it’s not planned just yet, but it’s something I’d love to support once the iPhone version reaches a more complete stage. One step at a time!

Really appreciate the thoughtful feedback. 🙏

1.1 x 1 should be 1.1 not 11

 

[aoifh]

1.1 x 1 should be 1.1 not 11

Got it — totally agree that 1.1 x 1 should return 1.1.

I just tested it on two iPhones and it seems to return the correct result (1.1), so I’d love to try and reproduce the issue. Could you let me know your device model and iOS version?

Thanks for pointing this out!

 

[cjsuk]

Good attempt but I think a calculator app is the one thing you probably need a skeuomorphic UI for. You need accurate, deterministic entry and that means large visual cues as to where the buttons are. I still use a physical calculator with tactile keys for this reason when I'm doing anything which requires more than my brain. Entry errors are the main source of failure from experience.

From a professional side (I'm an engineer by trade), I'm averse to paying for something this simple for the design aesthetic only. Free42 for example, which is a faithful and accurate recreation of the HP 42S scientific calculator has numeric solver and integrator, is programmable, has all scientific functions, stats, complex numbers and matrices. And is free on iOS, macOS, Windows, Android. And as you guessed from the name, it's free. And the interface has been stable since 1987 🤣

 

[aoifh]

Good attempt but I think a calculator app is the one thing you probably need a skeuomorphic UI for. You need accurate, deterministic entry and that means large visual cues as to where the buttons are. I still use a physical calculator with tactile keys for this reason when I'm doing anything which requires more than my brain. Entry errors are the main source of failure from experience.

From a professional side (I'm an engineer by trade), I'm averse to paying for something this simple for the design aesthetic only. Free42 for example, which is a faithful and accurate recreation of the HP 42S scientific calculator has numeric solver and integrator, is programmable, has all scientific functions, stats, complex numbers and matrices. And is free on iOS, macOS, Windows, Android. And as you guessed from the name, it's free. And the interface has been stable since 1987 🤣

Totally agree with your points — minimalism definitely isn’t for everyone, and I think that’s totally fine.

I’m actually an engineer too, but I’ve always preferred minimal, clean interfaces — so this app was really designed for people who feel the same. It’s less about feature depth, and more about the mood of the interaction. I totally understand how that can feel limiting (or even boring) to users who need more visual or functional feedback.

That said, I really appreciate you taking the time to share your thoughts — and Free42 is a great reference. I think it’s awesome that there are tools like that available, and I hope mine can just offer a smaller, clean alternative for a different kind of user.

Thanks again!

 

[arw]

Got it — totally agree that 1.1 x 1 should return 1.1.

I just tested it on two iPhones and it seems to return the correct result (1.1), so I’d love to try and reproduce the issue. Could you let me know your device model and iOS version?

Thanks for pointing this out!

I guess I found the cause: If you want to stick with . for decimal notation although , is used in various regions (like Europe), you have to respect the local numbering scheme set in:
Settings>General>Number Format

Two personal remarks:
- I appreciate your approach of displaying the current number / operand in a larger font than the whole term.
You said "no gimmicks" and maybe I'm just spoiled by 'Solves' but I'd really like to see that the calculation gets solved on-the-fly as it evolves without having to press =.
But as this probably requires the lines to be switched, it would also significantly alter your design / appearance.

- From a usability standpoint, the location of the delete key in the exact opposite direction of the displayed input / term is suboptimal. Perhaps this is one of the trade-offs of the cleaner look but imho it should be as close as possible.

 

[aoifh]

I guess I found the cause: If you want to stick with . for decimal notation although , is used in various regions (like Europe), you have to respect the local numbering scheme set in:
Settings>General>Number Format

Two personal remarks:
- I appreciate your approach of displaying the current number / operand in a larger font than the whole term.
You said "no gimmicks" and maybe I'm just spoiled by 'Solves' but I'd really like to see that the calculation gets solved on-the-fly as it evolves without having to press =.
But as this probably requires the lines to be switched, it would also significantly alter your design / appearance.

- From a usability standpoint, the location of the delete key in the exact opposite direction of the displayed input / term is suboptimal. Perhaps this is one of the trade-offs of the cleaner look but imho it should be as close as possible.

Thanks so much for the detailed feedback — really appreciate it!

I’ll make sure to adjust the decimal input behavior in the next version to better respect local number formats, as you mentioned. That’s a great catch.

Glad to hear you liked the font treatment — I wanted the current input to feel a bit more focused.

Your suggestion about switching the line order (putting the result on top) and showing results on-the-fly without needing to press = makes a lot of sense — I totally see how that could make things feel more fluid. I’ll definitely explore this interaction pattern further, and Solves is a great reference for that.

Really appreciate you taking the time to share this 🙏

 

[User #07242024]

Thanks for supporting iOS 15. But why is the margin big? Why not expand to full screen.

 

[aoifh]

Thanks for supporting iOS 15. But why is the margin big? Why not expand to full screen.

Thanks so much for trying it out and for your support!
If you don’t mind me asking — are you using an iPhone or an iPad?

 

[aoifh]

I guess I found the cause: If you want to stick with . for decimal notation although , is used in various regions (like Europe), you have to respect the local numbering scheme set in:
Settings>General>Number Format

Two personal remarks:
- I appreciate your approach of displaying the current number / operand in a larger font than the whole term.
You said "no gimmicks" and maybe I'm just spoiled by 'Solves' but I'd really like to see that the calculation gets solved on-the-fly as it evolves without having to press =.
But as this probably requires the lines to be switched, it would also significantly alter your design / appearance.

- From a usability standpoint, the location of the delete key in the exact opposite direction of the displayed input / term is suboptimal. Perhaps this is one of the trade-offs of the cleaner look but imho it should be as close as possible.

Just released a new version that addresses some of the issues you mentioned:
• You can now directly edit the calculation as it evolves
• The layout and logic have been adjusted for a smoother experience
• Decimal format now better respects system locale settings (e.g. , vs .)

Your point about the delete key location also makes a lot of sense — I’ll be exploring ways to improve that in future updates without compromising the overall simplicity.

Always open to suggestions, so feel free to share more thoughts anytime. Thanks again! 🙏

 

[User #07242024]

Thanks so much for trying it out and for your support!
If you don’t mind me asking — are you using an iPhone or an iPad?

I’m on iPhone SE 1.

 

[Beards]

Just released a new version that addresses some of the issues you mentioned:
• You can now directly edit the calculation as it evolves
• The layout and logic have been adjusted for a smoother experience
• Decimal format now better respects system locale settings (e.g. , vs .)

Your point about the delete key location also makes a lot of sense — I’ll be exploring ways to improve that in future updates without compromising the overall simplicity.

Always open to suggestions, so feel free to share more thoughts anytime. Thanks again! 🙏

Nice to see you have looked at the pricing structure. Now free for the basic version gives a much better understanding that will tempt users who value the app to take up either the monthly or yearly plan. Personally it would be the yearly plan I would adopt.
Now free I have just downloaded and will give it my attention at the weekend…. This again is why I mentioned make the initial app free:- It tempts users to download and try knowing their initial use is free. Further with a much lower plan it does not throw would be customers away.

 

[arw]

Just released a new version (...)

And some feedback in return .
1. Yes, decimal format works as intended (as far as I can see).
2. Your app inserts a space character before and after an operand. But they are not linked. If I want to delete an operand, I have to tap 'delete' multiple times because the space characters have to be removed separately.
This problem also holds true for editing the calculation as I can place the cursor before or after a space character.
This can result in having a space character between two digits. Like 1 +1 2 instead of 1 + 12.
3. Please make the haptic feedback optional.
4. Please revise the logic how brackets are handled:
(1 + 2 should result in 3 even without closing the bracket, not 2. [see screenshot]
I have no clue about writing an app but can't you simply pass the input to an existing solver or do you have to code all mathematical operations from scratch??

I'm glad you reconsidered and offered the app for free to test...

 

[aoifh]

I’m on iPhone SE 1.

Thanks for the feedback! The margin is actually part of the design direction — I wanted to keep some breathing room around the content for better visual balance.
That said, I totally understand that on smaller screens like the iPhone SE (1st gen), space is more limited. I’ll definitely take a closer look at how to optimize the layout for your device. Appreciate you bringing it up!

 

[aoifh]

Nice to see you have looked at the pricing structure. Now free for the basic version gives a much better understanding that will tempt users who value the app to take up either the monthly or yearly plan. Personally it would be the yearly plan I would adopt.
Now free I have just downloaded and will give it my attention at the weekend…. This again is why I mentioned make the initial app free:- It tempts users to download and try knowing their initial use is free. Further with a much lower plan it does not throw would be customers away.

Thanks so much for downloading and for taking the time to share your thoughtful feedback — I really appreciate it!

You're absolutely right — lowering the entry barrier by making the app free and offering more affordable plans is exactly what I hoped would encourage more people to give it a try without pressure.

At the moment, the UI only shows the monthly plan due to a layout adjustment, but I’ve already planned to bring back the yearly option in an upcoming update — especially for users like you who prefer it.

Thanks again for the support, and I hope you enjoy using the app this weekend!

 

[aoifh]

And some feedback in return .
1. Yes, decimal format works as intended (as far as I can see).
2. Your app inserts a space character before and after an operand. But they are not linked. If I want to delete an operand, I have to tap 'delete' multiple times because the space characters have to be removed separately.
This problem also holds true for editing the calculation as I can place the cursor before or after a space character.
This can result in having a space character between two digits. Like 1 +1 2 instead of 1 + 12.
3. Please make the haptic feedback optional.
4. Please revise the logic how brackets are handled:
(1 + 2 should result in 3 even without closing the bracket, not 2. [see screenshot]
I have no clue about writing an app but can't you simply pass the input to an existing solver or do you have to code all mathematical operations from scratch??

I'm glad you reconsidered and offered the app for free to test...

Thanks again for the detailed feedback — really helpful as always!

Glad to hear the decimal format works well now.

You're absolutely right about the spacing issue — I added spaces for readability, but the editing experience does suffer as a result. I’ll definitely rethink this behavior.

Haptic toggle — noted! I’ll make that optional in the next update.

And regarding the solver — I’m actually using an existing math library under the hood, but it doesn’t always cover every edge case perfectly, so I still have to add some manual handling and tweaks around it. That said, I agree there might be better or more flexible solutions out there, and I’ll definitely keep exploring to improve the logic and reliability.

And yep, offering it free for now is exactly so I can collect feedback like yours — thanks again for trying it out!

 

[wonderings]

I use ChatGPT for anything math I need. It is not complicated but it handles everything with ease. I can see calculators going the way of the dodo bird when you can do everything in on place, including dropping in a picture and asking it to calculate or do various other tasks based on that.

 

[aoifh]

I use ChatGPT for anything math I need. It is not complicated but it handles everything with ease. I can see calculators going the way of the dodo bird when you can do everything in on place, including dropping in a picture and asking it to calculate or do various other tasks based on that.

Haha fair point — ChatGPT can do everything, just like a Swiss Army knife can open wine bottles, cut ropes, and do surgery in a pinch 😄
if pure utility is the goal, calculators probably don’t stand a chance against ChatGPT

But this app actually isn't just about being a calculator. It's the first experiment in a small series exploring minimalism as a lifestyle and design philosophy — something calm, focused, and intentional, rather than just functional.

So while it may look like a calculator, the intent goes beyond that. It’s not something I threw together — a lot of thought went into the curves, spacing, typography, and flow.

If you’re curious, feel free to check out the post I shared or visit the website — it might give you a better sense of what this project is really about 🙂