Mobile app

I have my data source file ready in google sheet and tried to build mobile app using Appsheet but not getting the desired user interface and want more precise and filtered data. So I can use the mobile app in a better manner. It is not mandatory to use Appsheet, even customized mobile app will also work. It is a very small and simple application and having hardly 15-20 coloums of data and need the shortest time span for development.