Formerly Amazon Underground, the Appstore is Amazon’s storefront for Android apps. Get it here. Many apps that are region restricted in the Google Play Store can be found in Amazon Underground.

Official Non-Play Store Releases

Here are some excellent apps that are available officially from their developers outside of the Google Play Store. You can even pay for their premium versions if you’re unable to buy apps in the Play Store.

Web Browsers

Mozilla Firefox (Direct, x86)
Dolphin Browser (Direct, Amazon)
Opera (Amazon)
Flash Player (Direct)

Messaging

Telegram (Direct, F-Droid)
WhatsApp (Direct, Amazon)
Viber (Direct, Amazon)

Media

NewPipe (F-Droid)
VLC Media Player
Kodi (Formerly XBMC)
 KoRe (Kodi Remote)
 MediaInfo

Other

 Nova Launcher (Direct, Beta)
 Nine (Buy key for $14.99)

Utilities

Teamviewer (Direct, QuickSupport, Meetings)
Download Navi (F-Droid)
Acrobat Reader
RAR for Android
G-NetTrack Lite (Direct RAR File)