BillGrid.com - BillGrid is an easy to use online invoicing, billing and expense management system that will save you time with tracking clients projects, expenses, invoices and payments.
Argus - Collections management for museums & galleries
ChargeOver - ChargeOver automates recurring billing, subscription billing, & payment acceptance. A SaaS that integrates with Xero, Quickbooks, & has an API. Free trial.
Meow Playground - Imagine Club Penguin with cats!
Elorus - A super-easy online invoicing & time tracking software
CPPS.io - CPPS.io is a clone of Club Penguin, you will have the same experience as if Club Penguin was still around, with free membership custom features and more, come join CPPS.io a great alternative to Club penguin.