Seems like false sense of security. It only updates every 10 minutes or so. If you are really worried have them just call you and put their phone in their pocket. That way you can listen in and call 911 if needed.
Waiting 10 minutes for a GPS update doesn't seem to actually increase safety in any noticeable way.
I haven't downloaded the app myself. However, I was under the impression the 'virtual walk' was some separate feature that when turned on, allows the person to monitor your whereabouts in near real-time. (like could watch a tiny dot moving on a map as you walk).
One update every 10 minutes is way too infrequent. I feel like the majority of walks people could use this with would take less than 10 minutes ...
I go out for mega long bike rides in areas with very spotty cell coverage (Silicon Valley). This app is great because when my spouse wants to know where I am she can initiate the request, and I can keep my hands on the handlebars and keep rolling. I only wish they had thought to allow choices other than 'phone ring, wait 5 minutes'. I'd have prefered to set the notification type and delay. I hope the GPS battery drain for this feature is low (as compared with Garmin Connect, Strava or Glympse). 10 minute intervals sounds great.
Waiting 10 minutes for a GPS update doesn't seem to actually increase safety in any noticeable way.