Nowadays, tunneling is applied to a variety of constructions such as subway station, water supply tunnel and underground mine. Tunnel safety is one of the most important factors of construction. Most tunneling is operated in remote area that is difficult to reach. This research aims to develop an alternative software for Android smartphone, which use for estimating preliminary rock mass stability and suggesting support method for the early state tunnel. Suitable rock mass classifications for tunnel are rock mass rating (RMR) and rock mass quality (Q system). They are applied to the application. Android operating system is chosen because it is the most popular operating system in the world. The application is programmed by the official programming software from Google, the Android Studio. PSU-RQ is the name of this application. PSU-RQ is easy to use because it reduced the complexity of the theories by numerical logic. The application results are verified by comparing with Excel standard worksheet. PSU-RQ is reliable and accurate. The application is tested in a tunneling case study as an example. Whenever a smartphone is available, the user can estimate preliminary rock mass stability and support method of tunnel instantly. However, long-term stability investigation is necessary.