Device Tracker Plus is governed by the settings that you have set up on your device, the app works via GPS and location services; so, as long as you accept full permissions during set-up, your device has constant access to the internet and the locations settings are set to high we would expect the following results:
iOS and Android devices will track within a 10m parameter.
Occasionally, you will find location pins in areas that you have not been. Please do not worry, this is not a fault; basically when your device switches WiFi signals or from WiFi to mobile data your device will ping the transmitters to triangulate your exact location, from time-to-time this can result in a pin appearing in a location that you have not visited.