How to clear FF4 storage (Android)
Be sure to save all orders (preferably on server) BEFORE you do the steps below.
1. close FF4.
2. Tap Android settings. (icon looks like a gear)
3. Tap "Apps & notifications".
4. Tap "FFv4" (or find it in list of all apps).
5. Tap "Storage & cache".
6. Tap left garbage can (below it says "clear storage").
7. Tap ok.
You'll need to sign up again when you open FF4.