What I've found so far with the windows binary is that the installer appears to work, but launching the wallet fails after that. Going to try the following:
1. backup my C:\Users\...\AppData\Local\byteball-test
2. Delete the folder above
3. Reinstall using the binary
4. Attempt to reload my wallet from the backup.
And how step to backup via android device?
Unfortunately, the usual methods of backup don't work for Byteball. This is because of private payments, which are stored only in your local database and cannot be restored from a seed. Desktop users can backup the entire app data folder C:\Users\...\AppData\Local\byteball-test but you have to do it every time you send or receive blackbytes (or any other private asset), which is not something I would recommend.
The right way to protect your funds against loss is to create a multisig wallet. Any wallet with redundancy will do, e.g. 1-of-2, 2-of-3, 1-of-3. With multisig, if any of your devices is lost or fails, you'll be able to use the remaining devices to move the funds to a new wallet.