After several users reported that all their fleets had been deleted from their apps (along with the rest of the user data), I have researched into it because, though the app update proccess is handled by the Android system, this should not happen. After some research it looks like this problem arises from the latest update of the Android Webview , a key Android system component. My apps are web based and make use of the Webview component of the Android system. Looks like Google has done something different this time (a bug?) and all user data of all apps based on Webview is being deleted with the latest update of this component. So, please, please, do a frequent backup of your data! You can do this from within the app: - Go to the "Saved Fleets" screen - Tap on the top-left button - Choose the way you want to do a backup. If you have an active user, you can also do a backup to "the cloud" from the top-left button of the main screen.