BurnTheBoats is a free goal-setting platform that uses irrevocable social pre-commitments to keep you motivated. It's based on studies from NYU and UT Austin.

First, write your commitment contract and list friends to hold you accountable. But don't tell anybody yet! Studies show that sharing your goal immediately will make you less likely to achieve it. Instead, we'll send an email to your friends on the due date. By thus committing yourself, you stay motivated to stay true to your word. The only way to cancel the email is to pay a cancellation fee, which you choose upon creating your contract.