Everything you need / unneeded detail
I found this app extremely useful to find suggested routes through the city. The interactive map is amazingly useful. However, the timing was unreliable. U just used their suggested routs, ignoring the useless precision to which the app claims the Berlin transport system follows (all the buses were late anyway and even the trams were off time a bit as compared to the app). Overall, it was an invaluable aid to our visit through the city.
Takeitfromme0001 about
BVG Fahrinfo: ÖPNV Berlin, v4.0.12