Github is a really awesome tool. It's where most open source project live. In my case, I use github as a means of control and tracking. I've been doing so many projects in my free time, but however I do not have a record or something that can show what I've been doing. For example, I made a game a couple of years ago, but somehow lost the code. So I can't actually state that I've made a game.
Github too works really well with Kicad. Kicad is an electronic schematic capture and pcb design tool. It works well because kicad stores all of its files in text format. Thus github is a good way to manage my circuits.
Github, I believe will also help me keep a track of where I'm coming from and where I'm going. I've discovered recently that using github make me use it even more.