Low latency video streaming from one Raspberry PI to another:

PI with a camera: raspivid --bitrate 3500000 --profile high --level 4.2 -vf -hf -n -l -o tcp://0.0.0.0:5001 -w 1920 -h 1080 -fps 0 --intra 0 -ss 0 -m raw_tcp

PI with a monitor: hello_video_active.bin -h 0.0.0.0 -p 12345 -l

Low latency video streaming from one PI to an android(>=5.0) smartphone:

PI with a camera: raspivid --bitrate 3500000 --profile high --level 4.2 -vf -hf -n -l -o tcp://0.0.0.0:5001 -w 1920 -h 1080 -fps 0 --intra 0 -ss 0 -m android_motion

android viewer is here: https://github.com/maroviher/RaspiCAMStreamer