Patreon - Patreon enables fans to give ongoing support to their favorite creators.
Patreon Developer - Funding the arts across the web with Patreon's new API
Ko-fi - Ko-fi offers a friendly way for content creators to get paid for their work.
Drip by Kickstarter - A new way to back creators. A Patreon competitor.
Tipeee - "Tip" the creators you like.
Cloud Patron - Open source Patreon alternative