Doogee S90 modular phone comes with an external battery pack, night vision camera and walkie talkie Modular smartphones have not had much success in the past, Google’s Project Ara was cancelled before released, while LG’s G5 was a commercial flop. But the idea of a smartphone that can be upgraded via add-on parts is so enticing that it was only a matter of time before another attempt was made. This time, the modular handset comes from Shenzhen-based Doogee, a relatively small start-up specialising in selling budget handsets. we put the S90 dubbed the most versatile and unbreakable smartphone to the test