CodeTriage - Help out your favorite open source projects and become a better developer while doing it.
24 Pull Requests - 24 Pull Requests is a little project to promote open source collaboration during December.
BountySource - BountySource is a funding platform for open-source bugs and features.
Gitpay - Add bounties to solve Git issues from projects.
Mergefly - A modern UI for GitHub pull requests
Ko-fi - Ko-fi offers a friendly way for content creators to get paid for their work.