1. It sticks only to a flat, clean surface, such as a tile or windshield. However, it does not have an inclination adjustment, so forget about using it on a windshield because it will be looking elsewhere. Also, no car has a flat surface above the lever to place it there, even for GPS use.
2. If you have a phone case, it is useless because you have to stick a metal sticker on top, which is difficult to hold. If you don't have a case, you probably wouldn't want to put a plate with a sticker on the body of your phone.
3. If you manage to put it somewhere, it won't change position or be removable again. If you somehow remove it, get a silicone hot glue gun to stick it somewhere else.

Very easy to use for the car, you can leave your mobile phone directly and it doesn't move at all from its position!