I did research on the ideas for great app and I came up with the idea of Quiz game and then I have created it with database and some static questions.
Once I have created it but then thought that this is not the proper way to improve the knowledge as static questions will be repeated every time.
So, I did search for the online API for quiz questions and found trivia API and then I have loaded the questions from the API.
Now the app have dynamic questions and with dynamic number of questions (You can select 10,20,30) and can improve your knowledge.