So there are two things here:
- Live view of the camera - with the Blink approved version you can “view” the live feed (though note the battery life supports about 20,000 seconds of video) through the ST app
- Turn on video recording - this can’t be done currently, working with Blink on this for the future pipeline, however as @krlaframboise pointed out you can arm the camera when someone steps on the mat and if there’s movement in front of it then it will automatically record a video (depending upon your configured video recording length) and raise a motion event notification thereafter.
BTW just a little trick, if you’re interested. This isn’t an official blink functionality but more of a quirk I’ve noticed while testing the camera, if you force a the camera to take a picture while it is armed it tends to set off the motion detection and consequently turns on video recording. Most likely a firmware bug and could be fixed by Blink in future. However for now it could be used a proxy trigger to turn on video recording.