This app is a Tasker plugin to trigger a vibration pattern on the wearable device only, for a discreet notification tap where a popup is not required.
To use it create a new Tasker task and add TTW from the plugins. You'll be able to change the type of vibration tap within the configuration screen.
Any Tasker event can be used to trigger TTW, examples include getting a tap when your WiFi is down, when your phone is low on battery or even just at scheduled times.
Requires Android Wear, it does not work with non-wear devices.
Requires Tasker
https://play.google.com/store/apps/details?id=net.dinglisch.android.taskerm