You can restore Sober Time's Premium to an app installation if you've purchased it in the past. You need to be logged into your device with the same Google or Apple account you originally purchased. Because of the two different App Stores, restoring your purchase across platforms is not currently possible.
1. Open the main menu button located on the top-left corner of the Home page.
2. Tap Premium.
3. Tap the restore button located at the top-right corner of the page.
4. After that, tap the Find button.