From the app itself:
The Autogenic Drainage app provides a customizable timer with voice commands to aid in doing autogenic drainage. Autogenic drainage is a breathing exercise that is used to clear mucus from the lungs in people with lung disease. Autogenic drainage requires no equipment and is done entirely through controlling your breathing.

This app contains a default autogenic drainage session that was customized by a person with cystic fibrosis and also contains a fully customizable session if the defaults do not work for you. You can customize the length of every inhale, exhale, time holding your breath, and total number of breaths in each phase of autogenic drainage. Hit start and voice commands tell you when to breathe in, hold, and breathe out. The timer also displays how long your session is, the current breath number, and how many breaths you have remaining. The app also contains a reference section.

This app was designed to the specifications of a single person with cystic fibrosis and was developed as an aid in doing autogenic drainage for people with cystic fibrosis or perhaps other lung diseases. This app was not developed by doctors, respiratory therapists, or any other medical professional. This app is not intended to replace any existing medical treatment and should be only used as an aid to people already doing autogenic drainage or those eager to try it.