Pine64, the team behind the $99 Pinebook, has announced they will begin working on a cheap Linux-based smartphone. Dubbed the PinePhone, the handset will be built around Pine's low-spec, low-cost Pine A64 single-board computer. Designs haven't been finalized, but dev kits are set to be released on November 1st with a projected device release date of mid-2019. The PinePhone is estimated to sell for $100.
https://www.notebookcheck.net/Pine64-maker-of-cheap-Linux-laptops-may-be-making-a-cheap-Linux-phone.346011.0.html