Formerly the Amazon AppStore, Underground is Amazon’s new 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.
APK Mirror Releases
APK Mirror is the only unofficial repository of Android apps copied from the Google Play Store that I trust. I have used numerous apps from this site myself and have never encountered security issues. If a popular app that you like isn’t available in your region from the Store then you can probably find it on APK Mirror. Here are some i find noteworthy.
Microsoft Office for Android
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