Amazon Customer 3 I'm pleased with the functionality; I don't use the app, so while I'm not getting any advanced features, just the tracking and basic functionality are great. I'd give it a five out of five just for that.Unfortunately, the interesting and clever design of the battery panel on the bottom of the mouse means that if you tend to lift your mouse slightly while using it -- as many of us do, particularly if you have a relatively small mousepad -- results in the battery panel flexing and making a squeaking sound. Which is a little funny as someone who remembers when mice would wear out and squeak when they still used balls to track motion, but it's hard to excuse at this point.I don't know if I'll return it, but I certainly can't recommend it (particularly at this price point) with this apparent design defect. It feels better than the Anker I was using before, but the squeaking is really irritating.