It's sad to see that. The project is interesting, but making it WiFi only restricted immensely its use. Although it seems obsolete tech, many countries still use 2G GSM phones (my phone is only GSM in fact). Adding a cheap SIM800 chip on a small removable board would turn this into a real phone, and the sales from people who needed GSM would help to cover for further development for the 4/5G version.