can't beat this for a bit of fun. £28 currently (active price management so will fluctuate).
I use Eken & Explorer Pro, but this has similar specs to the Eken h9.
WiFi control and stream.
V3 4K WiFi action sport camera, allowing you to record the excellent moment when doing sport
Suitable for extreme sports, outdoor sports, marine sports, bicycle, car DVR, diving, home security, etc.
Adopts Allwinner V3 chipset, operating smoothly
With Sony IMX179 CMOS sensor, for shooting high quality images