Firefox Marketplace Apps Stop Working on Firefox 47+ for Android
The Firefox feature that enables you to run Firefox Marketplace apps on Android will no longer be available starting in Firefox version 47.
After you update to Firefox 47, or a newer version, apps that you've installed from the Firefox Marketplace will stop working. When you start an app, it won't run, and it will tell you The app requires a compatible Runtime to run, in this case Firefox For Android.
There are a few ways to work around the change.
Workaround #1: Look for the app on the Web
In many cases, Marketplace apps are also available on the Web and can be accessed from a tab in Firefox. Search for the app on the Web using your favorite search engine.
Workaround #2: Look for the app in the Google Play store
In some cases, Marketplace apps are also available in the Google Play store. Open the Google Play store and search for the app.
Workaround #3: Use an alternative app
In a few cases, Marketplace apps aren't available elsewhere. For those apps, you'll need to switch to a different app that provides similar functionality. Search for web apps using your favorite search engine, or search for Android apps in the Google Play store.