Forgive the topic res! I've been hunting down an answer to exactly this for ages and have a few reccs. Hopefully this is useful to other people who stumble on this! Even if the OP is probably well past needing the info
From my experience in a supervisor / managerial role, we've burned through a number of different options. The StaySafe app worked well enough, but wasn't as compatible with some of our hardware as we would have liked. Blackline's Loner Mobile app (this one) worked much better, though. Smoother overall. Better feature set, and it just *works* which is a godsend when you're pushed for time Can personally recommend. Six months on and we're still using it, no issues.
