Dialog "Amazon AppStore Required" - apps prevented from starting Many of my apps were downloaded from the Amazon AppStore as part of their "Free App of The Day" (henceforth FAoTD) program. This program was recently discontinued in favor of Amazon Underground - an all-encompassing shopping app, similar to any number of their other shopping apps for Android. Since I was not interested in continuing with Android Underground, I uninstalled the Amazon App, AKA Amazon Shopping, AKA Amazon for Android apk.

The next time I tried to run one of the apps from Amazon from the FAoTD, I encountered a dialog and immediate shutdown of the app when acknowledged with the OK button:


  Amazon Appstore Required
  
  It looks like you no longer have an Amazon AppStore on your device. Please install an Amazon AppStore and sign in with your username and password to use this app.
The solution is as stated, though it was not easy: re-install Amazon AppStore. Amazon Appstore is not distributed from Google Play any longer (though it was when I first installed it). It must be installed from amazon.com (as a 3rd party app - Settings &gt; Security &gt; Unknown Sources must be enabled), and updated to the latest version - Amazon Underground for the dialog to stop appearing when starting "Free App of The Day" apps. This left the device with an unwanted app with necessary space consumed unnecessarily.

After the installation, I was able to test the correct opening of certain apps I got through the FAoTD program. I tested starting them both ways: from the "Your Apps" list from within Amazon Underground, and outside that environment, directly from the launcher: 


2Do (which had a lot of checklists for Books and Movies I would have lost),
DoggCatcher,
mSecure,
Monument Valley, and, I presume, the re-enabled startup of
Nearly 2 dozen other apps and games.