It's good-4 stars from me- plus suggestions – Wear Ditto Review

Needs to be close to your body to feel it. The vibration is strong but it does not matter. If it's not touching you and just hanging loose in your pocket you may not feel it. It's easy to lose, needs a "last location" feature. That way I can check the app and say "oh I was at work last time it was connected" or "I was at my girlfriend's house last time it connected."
Review by dspiry on Wear Ditto.