I'm also moving to IOS. I really liked aCar and was looking for alternative to, when I found this thread/forum. GasCubby seems like a clear winner if I can easily transfer my data over. Hope it happens soon.
If you send a full back up from aCar to the help desk, I will attempt to sync that data to Fuelly when the next alpha version of aCar 5.0 is released to me. I should get the newest version in the next week.