App Cloner enables you to create clones or duplicate an installed app on your phone. You can create and install multiple working copies of your existing apps. That’s especially useful when a given app only allows one account login at a time.

Before apps such as Facebook Messenger rolled out adding multiple account support, many users had to download modded APKs of the apps to be able to log in with different usernames on the same device.

App Cloner FAQ
How do cloning apps help us with using mu