I have used both GV Mobile (prior to removal) and GV Connect. GV connect has more configurable options but it is not stable. The developer has been VERY supportive, but with app store turnaround, just how supportive can you be, (one release a month maybe?)
I am going to hang in there with him, it is only an occasional drop out of the program, but if my business depended on it, I would have to say GV Mobile...they are very similar.