GTBee is a to-do list that integrates with Beeminder. Create tasks with deadlines and Beeminder will charge you if you dont complete them in time.
Beeminder will email you if you miss a deadline to confirm its going to charge you. If you want to test, you can reply "testing" to the email to void the charge. This only works once though; after that youre on the hook!
Youll be prompted to authorize GTBee on the Beeminder website - this is a one-time step.