Wi-Fi hotspot without cell carrier permission. If I send data back and forth between my iPhone and my MacBook, it’s none of the cell network’s business what that data is. They already charge me for the data I send between my iPhone and their cell network, it’s none of their business what I do with that data locally.
Sort apps in App Store when browsing and searching. I want to sort apps by average review, by average review for current version, by original release date, by current version release date, by name, by number of downloads, by number of downloads for current version, by price, and so forth.
Ability to assign trust to apps myself. I bought the iPhone, I own the physical device, therefore I am the one who should decide which programs can and cannot run on it. If Apple does not want to put a certain app in their App Store, fine, let them not. But for them to prevent me from installing apps from other sources, that is contrary to the idea that I own the device.
Home screen rotate to landscape mode on iPhone.
Documents folder.
Ability to remove pictures from camera roll after placing them in other albums.
Rotation lock that works in landscape as well as portrait.
Ability to view saved WiFi passwords by entering Apple ID and password.
Photos app should show full-res versions of pictures.
Folders within folders.
Unlimited icons per folder.
Place app icons in any grid location, not just “fill from top left in order”.
Option to make tapping a number while viewing a contact pop up a question asking whether I want to Call, Edit, or Cancel. Same for tapping an email address, etc.
Ability to choose a different app to launch from the lock-screen Camera button.
Quick access to Brightness adjustment from a physical button.
An option to have the enclosing folder close after launching an app from it.
Option for custom lockscreen behavior. This might actually be my biggest reason not to upgrade until a jailbreak is out: I really like my custom lockscreen that shows the current phase of the moon on a black background.