Notary Gadget isn't for Signing Services; it is for notaries. I use Notary Gadget and like it. NG isn't just a tracking program. It gives reports like Expenses, Income, Mileage, Customer Lists, Profit & Loss.
I have not used Snap Docs, as mentioned elsewhere in this string. Fees from many, perhaps most, Signing Services using Snap Docs are very low and undesireable and unprofitable in my way of thinking.