Mobile game app as challenges about informations

I am looking to develop a mobile quiz game app that is both fun and challengy. The app should provide informative challenges to the user and will include features such as an immersive multiplayer mode and score tracking. The user can form teams or alternatively compete versus each other in single player mode. Time limits can also be set if desired. The app will not require 3D graphics only 2d which will help to keep development costs low. This app should provide engaging gameplay and help to expand the user's knowledge. The app needs a database for quiz questions which will be updated constantly. Also we might need a voice chat between the players.