This product is great if you do not want to use your keys and to monitor who enters your home. The app has the instructions to install, which are very easy follow and to do it, just need a screwdriver and that´s all. Before you try to install it or even before purchasing the lock, check that your deadlock is compatible with this device, if not, you may need to buy one. The only cons I could have is that since I installed the app, my cellphone´s Bluetooth activates/deactivates randomly. 
The material looks pretty good, you can use your keys just in case you cannot open it with your cellphone. I have about 3 months using it and it is working with the initial batteries.
One thing I liked is that has a feature where if you are near the door, the locks open automatically.