This timer gives you the ability to set up your zazen-time and a preparation-time before. The signals are generated by a simple sinus-wave. So, you get a real digital tone as a signal not a sample of a singing bowl or something else. Take this signal to act, to meditate or to open and close your sitting by tapping your own singing-bowl. The signals and times may be varied to your needs. The App may run in background or locked device, so the energy consumption is very low.