Office Ally provides a free billing / practice management software called Practice Mate. It really depends on the volume of claims to know if it's a good choice.
It's not very efficient and a lot of the tasks can be time consuming, especailly follow-up. How much time are you willing to give for a low cost software?
I prefer Kareo over OfficeAlly. It does have a higher price, but it's worth it for me.
Thanks,
Charity