When using PowerMiser your smartphone will automatically go into extreme power saving when you are not using it. "Idle Mode" will save your battery life when you lay your smartphone on a table or flat surface. "Pocket Mode" will do the same when carrying it in your pocket or purse. However, as soon as you grab your phone and start using it all powered down features immediately turn on which gives you 100% functionality in an instant. Cellular connectivity is never affected with PowerMiser.