Android: The US-only HTC One and Galaxy S4 'Google Editions' ship with a new and improved Camera app that adds features such as PhotoSphere and an improved settings menu. Thanks to some enterprising users, that APK installer is in the wild and available to anyone who wants to give it a whirl.
The last time a new camera app landed in the wild, you needed a rooted Android phone to make use of it. This time, you don't need root to install the updated app.
The new version features Photosphere, a helper tool for panoramic photos that appeared in 4.2, and it now works on more devices. As well, the app lets you use your phone's volume rocker to take photos. The new settings menu lets you switch flash modes, choose front or rear cameras, adjust the white balance, and tweak exposure times.
The new app was reportedly supposed to be part of Android 4.3, but it was moved to the Google Editions of the S4 and HTC One instead, and even though it comes with phones running Android Jelly Bean (4.2), it works on phones running 4.1 and Ice Cream Sandwich (4.0) as well. Your mileage may vary though -- in my case, it added a Gallery and Camera app to my phone as opposed to overwriting the original one, and other users have reported having to remove the original camera and gallery apps for the install to work. Some noted that they got some features, like the new UI and settings, but not Photosphere.
Either way, it's just an app install -- if it doesn't work for you, you can remove it. If it does, you'll get a great new camera app, completely free.