Fans of Amazon's Kindle app for Windows are in for some bad news, as the company will be removing it from the Store on October 27. The app is designed for Windows 8, but since the company never embraced Microsoft's Universal Windows Platform, it's still the one that you get on Windows 10.
Amazon is recommending that e-book readers use the existing Win32 app moving forward. The company sent the following email to Benjamin K. (via Windows Central):
For the past few years Amazon has supported two separate Kindle apps for Windows PCs. In order to provide our Windows customers with the best Kindle reading experience, we are simplifying our approach and focusing our efforts on the Kindle for PC app.
If you are currently using our other Windows app (Kindle for Windows 8) on one or more of your PCs, we recommend that you upgrade to the Kindle for PC app to get the best reading experience and latest Kindle features. We are regularly updating the Kindle for PC app, including recent features like multi-color highlighting, improved search performance, and support for textbooks.
To simplify the experience for Windows customers, we will remove the Kindle for Windows 8 app from the Windows Store on October 27, 2016. If you already have the app installed on your PC and wish to keep using it, you can continue to download and read books as you do today. If you uninstall the Kindle for Windows 8 app, you won't be able to reinstall it from the Windows Store.
If you have questions (or if you have a Windows RT device), please see our Kindle for PC help page.
Obviously, it doesn't say anything about the Kindle app for Windows phones. On the Kindle for PC help page that's referenced above, it recommends upgrading to the Win32 app; however, the Kindle for Windows Phone page doesn't make any references to being discontinued.
As for Windows RT users, you're going to want to make sure that you have the app downloaded before it's removed from the Store on October 27.
We've reached out to Amazon to ask about the phone app, as well as if the company plans to launch a UWP replacement, or even if it plans to wrap the PC application up as a Project Centennial app. Converting the desktop app seems like the most likely option, as it's the easiest option and the company relaunched its Amazon app as a hosted web app.