I had concerns of my dog escaping, so I bought a tracker (another than whistle), wasn’t happy with the tracking distance, so I bought another and another. Then I took a 3200 road trip staying at various places. I was trying to be cheap and not get a subscription tracker. After seeing how useless most non-subscription trackers were after 300 yards even though they advertised 3-7 mile range I opted to get whistle and give them a try. I’m sooooo glad I did.Whistle is more than I can ask for in a tracking unit!Note: you need to be in an area with cell phone range (specification AT&T, which seems pretty much every metropolitan area) I don’t recommend this product if your WiFi extends off your property AND there isn’t cellular network in your area... essentially if you live in extreme remote areas.Other than that Whistle is the best I have tested and gives daily activity such as distance, licking, scratching, and sets goals for your led depending on breed and age. This has actually motivated me to hit their goals with them and I have slowly gotten in shape and lost weight!The whistle app is robust and tracks you dog in my opinion every 3 min and if you fur baby escapes and you hit the track feature I believe or could be wrong, tracks your baby every 30 seconds or less on an google type map. For the features and functionality and health features, the best I’ve seen.Now let’s talk battery life. I walk my babies about 30-45 min a day; with that, the whistle go explorer lasts about 3 weeks which in my opinion is amazing, just need to charge it for about 4 hours or overnight.Another nice feature is that if they escape or leave your virtual fence that you set up around your property within the map, the app will alert you by a notification through the app, or text message, or through email, or all of the above if you really want your phone to blow up when they escape.I love the product so much that I decided to buy all three of my little ones a whistle. One of the units came from and it was blemished and even though I paid the brand new price, I feel that it was used in the battery life is extremely poor and only lasted about three days, so I returned it and bought another one and luckily it appeared brand new and the battery life matched the other two, so if you buy one and the battery life only lasts a short Time, just return it and get another one or buy it directly through their website as new.Yes there is a monthly or yearly subscription but think, if your fur baby were to escape or get lost, how much would you pay at that moment to get them back immediately.I highly recommend this product, it’s worth it and you get more than what you pay for in my opinion.