To follow up, do not waste your money on a Foxit subscription to get XFA support to file FBAR on your mobile. Not only is the app frustratingly buggy, it ultimately won't let you file your completed form. Shameful that any company would put software like this on the market.
BUT: If you have to fall back on the official online form, note that it allows you to skip entering addresses, which does save a lot of time.