[infomax]

DroidCam connected via USB on my Android smartphone makes a great 1080p webcam. The latency is minimal.

It has great linux support and works great with OBS (and its chroma key filter)

[ciarancour]

Seconded, I wasn't satisfied leaving droidcam streaming over wifi 24x7, password or no password, so I have a shell alias to unlock phone and open droidcam over ADB USB debugging.