APK will not install

If the phone says the app was not installed, the file did not arrive whole, or the phone will not accept it.

• Install from unknown sources may be off. Allow it for that installer in settings.
• If the download stopped halfway, download it again.
• If the same app is already there with an old signature, remove it first, then install the new one. Its data is deleted.

An APK signed with another key will not install over an app that came from Play.