Semisilent

Normally, you have two choices for cellphone calls: be available to called by anybody but potentially interrupted, or be able to focus and be unreachable. Enter SemiSilent with a much-needed third option.

With SemiSilent, you can choose which of your contacts you want to be available for all the time. Then you can set your cell phone to silent mode to save yourself from being disturbed by the rest of the world. If one of the contacts you selected through SemiSilent calls you, your ringer will be turned on so you don't miss their call.