I'd suggest projects based on Javascript or a similar easy to learn language, which lowers down the barrier to entry. You may want to check Countly (http://gith

I'd suggest projects based on Javascript or a similar easy to learn language, which lowers down the barrier to entry. You may want to check Countly (http://github.com/countly/countly-server http://github.com/countly/countly-server), a mobile analytics and push notifications platform.