[Zubersoft]

If the new device is also a Windows-based device, then load the Microsoft Store application (don't use a web browser), log in with the email address you used to purchase MobileSheets, search for MobileSheets and it should let you install the app without requiring additional payment. 

If the new device is an Android tablet and you have only purchased through the Microsoft Store, then you will have to purchase the Android version separately through Google Play.

Mike