This is a tool specifically designed to plan routes and view waiting times at bus and tram stops in Rome. Please, be aware that it doesn’t contain information about the metro and is only available in Italian. However, the interface is very intuitive, so you can still use it without any problems.
Unfortunately, the Roma Mobilità app is not available for smartphones in some countries. If you can’t install the app, it’s best to opt for Moovit or the web version of Muoversi a Roma (which has similar features and doesn’t require installation).