Intelligent Ringer - This app lives up to its name, because it really makes your call "intelligent". Its essence lies in the fact that your smartphone will recognize the environment in which to be. To be more precise, if you have noisy, the call is very loud, and if you have complete silence, or in the middle of the night, then a call is medium volume, so I can Wake you but not for all tenants. Using accurate manual settings, you can adjust all parameters of this application that it would have worked perfectly.