I bought a SQ-13 camera off AliExpress for $20ish, which streams over Wifi (it acts as an AP) and is about an inch by an inch cube. (It's small enough to be carried on my N-scale train cars for a train-eye view.)
I was interested in this one or a similar model (sq20) to be used as a dash cam with external supply as the internal cell doesn't last much. Can it be configured to connect to a wireless network and stream the video to a standard encoder/player on given address? I would use it to stream to a small NAS in order not to destroy the flash doing continuous recording. Hopefully it doesn't require a smartphone and a proprietary app to connect to its stream.
Not as far as I can tell - the SQ13 has a really dinky, shitty app that I wouldn't want to use for anything serious. I was unsuccessful finding any hacked firmware for it.