Zelos - A very simple app for mobile teams - tasks and chats on desktop and mobile.
Unlock - Monetize your content with a few lines of code
Google Groups - Google Groups allows you to create and participate in online forums and email-based groups with a rich experience for community conversations.
ZELF - Instant money in messengers
OnlineGroups.net - A hosted mailinglist manager service
MonetizeJS - Modern payment platform, no server required.