Switch to silent mode automatically?

Everybody knows, how annoying a ringing phone can be while in school, at work, in the cinema... Why not telling the phone in advance when it has to remain silent?

?Switching to silent mode in background

?Repeating silent phases

?Foolproof settings

?Every single phase or the whole application can be deactivated

?Never get disturbed by an annoying caller ever again!

此版本中的新功能：

?Added context menu: "Toggle active", in order to be able to switch a silent phase quicker to active/inactive

?Small bugfix