WHMCS - WHMCS is an all-in-one client management, billing & support system for online businesses.
Singscope - See your pitch analyzed as you sing
HostBill - HostBill is a powerful and flexible, all-in-one automation, billing, client management and support platform for online businesses.
Vocalist - Vocalist is an all-in-one music utility.
Blesta - Blesta is professional client management, billing, and support software.
Pitch-Chromatic Tuner - Tuner & Music Fitness Tracker