Have a land and sea rover I purchased the grandsons. Seems that Crookstone no longer supports the app so any owners are SOL as the device won't work without it. The "current" Crook-stone owners state via the customer support line …"our developers are working on getting an app"…. Don't hold your breath! Avoid this place and boycott purchasing from them!
I found the selection and price very favorable, and upon making my selection decided to purchase 2 watches instead of 1. Great service and delivery as they both came without delay and were packaged nicely from the manufacturer.