Is there some APP similar to jakdojade to search for public transport in Berlin?
The Berlin transport authority, the BVG, has an app for that for both iOS and Android. You can search timetables, find routes and use the phone as a ticket.
They have links on their website
The Android App Öffi is really helpful to navigate public transport all around the german speaking countries in central europe.
An alternative to the BVG app mentioned in the other answer is Citymapper, which has a nicer interface. Google Maps also gives decent public transit directions.