This is a mobile phone that is:
1) As open-source as possible while also being cheap
2) Easy to get parts for if you want to assemble one
3) Easy to assemble and repair
4) Free from apps with privacy concerns
5) Easy to write apps for

Currently, it costs about 50$ in parts, and all the parts are available on eBay. No BGA or other difficultly solderable ICs are used (with the obvious exception of Pi Zero). User interface is written using Python, and there’s a phone-tailored UI framework in the works (so far, it uses pyLCI for interfacing). However, even current state of it is further that other projects have come.