Build app for raspberry pi fluid flow meter

Hello I require an app compiled for a raspberry pi that will control filling system for a water tank. HARDWARE: - Raspberry pi2 Model B - Official raspberry pi touch screen - 32 channel I/O Board ([login to view URL]) - Flow meter (pulse output, 32 pulses per liter - max flow of 150l/min) - 4 chanel relay output ([login to view URL]) OBJECTIVE The screen needs to display an page similar to page one of the attached document each green button refers to an preset amount of water (175, 375 etc) so when the 175 button is pressed the pi will need to activate relay 1 and monitor the flow meter - when 175 liters has been dispensed to then deactivate relay 1. once anyone of the buttons has been pressed the screen then needs to switch to page 2 of the attached document which shows how much water has been dispensed and it will also need to contain a button which will then terminate the filling. once the filling has been completed then the screen will then need to go back to the home screen. Each of the buttons on the screen refers to a volume of water that needs dispensing. The split button is for a smaller amount of water which will be predefined.