Ive read a few reviews, I use it a lot, Ive loaded the up with $50 a time at least 4 times. Havent experienced any problems. Ive sent my wife gift cards for her app and she likes it as well. I like being able to use the map when traveling to find a nearby Sonic, I like the ease of paying without having to scrape up cash, I also like the receipt showing on the phone in case there was a problem with my order and I like getting free stuff every once in awhile. It doesnt work for call ahead orders and at the old Sonics that dont have the screens.
I do agree with someone who stated good luck in trying to get ahold of Sonic, they have an 800 number that is basically an answering service, I tried for several days to get in touch with Corporate on a non-app issue, finally a week later I get a call from local manager. I wanted someone higher up, but the issue did get resolved.