Automat
http://automat.wiki/Automated Testing for Newbies
Automat.site - purely online automation platform that is super easy to grasp and make use of either you are a developer or tester.
Learning curve is very short for it is perfect for beginners. And thanks to its modular structure and built-in version control system it is also very scalable and robust.
It is based on Javascript so those who are building WebApps fill find it very natural to start testing with it.
Member count: 1-10