Bountysource

Bountysource was a crowdsourcing website for open source bounties and since 2012 also for crowdfunding. Users (called "backers") could pledge money for tasks using micropayment services that open-source software developers can pick up and solve to earn the money. It also allowed large-scale fundraising for big improvements on the project. It integrated with GitHub using its bug tracker to check if the problem is resolved and connect the resolution with GitHub's pull request system to identify the patch. When the users agree that they are satisfied and the project maintainer merged the proposed changes to the source-code, Bountysource would transfer the money acting as a trustee during the whole process.