Okay, I bit. Apple's package includes a folding phone stand to keep your phone easily visible. Apple's price is $10 less than Amazon's (though it seems Amazon's package also includes a carry-bag).
Frankly, so far I'm far more impressed than I thought I'd be.
I travel a lot and, unfortunately, hotel gyms are germ-fests I've learned to avoid. (I used to frequent a wonderful high-end gym whose staffers were constantly wiping down the equipment with disinfectant, but you never see that in hotels or most gyms today, so your immune system can get a workout along with everything else.) Also, when traveling there's not always time, opportunity or favorable conditions for outdoor sessions. And so fitness has been a challenge. I've done in-room stuff in my hotels, which helps, but those workouts pose their own problems. For example I had a set of bungee bands which were great until one snapped and shot me right in the huevos.
So all in all, for a bit over a hundred bucks this seemed like something to try. After all, Apple has a 14 day return policy. So I picked one up between trips as a present to myself.
The unboxing process is very Apple-y. Nice packaging, good-looking palm-sized device, single-button operation, minimalist documentation that's easy to understand, AAA battery already installed. You're up and running in 10 seconds after you've downloaded the app. Pairing is done in the app; there's no separate Bluetooth pairing step. There are several apps available on the App Store from Active5; so far I've tried the main one. That app is a mix of excellent design and a few what-were-they-thinking elements (usually regarding small fonts for the inter-exercise screens) that I expect will improve with updates. You do not need sound to be turned-on to use the app. The actual exercise sessions are nicely formatted and interactive. You don't need to touch the phone at all during a session-- a double-squeeze on the Active5 puck advances you from set to set. It's integrated with HealthKit, so your metrics are compiled automatically and tracked over time.
For each set, there's a photo showing how to hold the device, what position you should be in and how to position the unit and exert the required force. That's the end of the photo. In your first attempt at each exercise, you calibrate the system by exerting your maximum force. From that point you're presented with a target force trajectory, and you attempt to build and ease your force as the target line rises and falls.
Ultimately: you do feel the workout! That tells me that it will indeed have a positive impact over the long term. The device and/or the app maintain knowledge of your exertions and track those over time, so your progress is quantified. Your body is working against itself, so there are no plateaus or limits that would require you to (for example) graduate to a heavier weight or a stronger band.
For those saying the device is unnecessary: certainly, you're correct. A gym membership isn't necessary either, nor are many of the accoutrements and gizmos people use, including the Apple Watch or Fitbit so many of us find useful. In fact, some of the comments here track nicely with comments about the Watch when it was introduced.
Ultimately, I'm positive about this device as a part of a daily routine. It's small and lightweight, about half the size of a typical short paperback book, so tucking it into my briefcase to accompany me in my travels is no issue. It is as well-built as any Apple product. It seems it will be effective. The workout sessions are quick but leave you feeling as though you've accomplished something.
Give it a try before judging.