Patreon - Patreon enables fans to give ongoing support to their favorite creators.
Newsletter Operating System - All-in-one dashboard to launch & grow your newsletter
Level Music - A new platform for independent artists, everywhere. In beta.
LetterHunt - LetterHunt connects you to 10,000+ niche, active newsletter writers to promote your product.
Apple - Available on iOS
Kickstart Side Hustle Newsletter - Dwarf-size newsletter with viral marketing case studies