Userbase

Userbase is designed to make it easier to manage your software business by helping you to do the labor intensive processes quicker so you can spend more of your time coding! Track your Software Sales, Supports Armadillo & Custom Key generators, Auto Email Merge, Bug & Enhancement Request Tracking, Send emails,newsletters to users based on product and/or version #, Track registration fees and taxes, Track Fraudulent users and registration id's, Reports and more.

Limitations:

Limited functionality, nag screen