I need ideas on paperless scheduling

hey guys so my girlfriends boss runs a hair salon and wants to put there customer scheduling on computer or paperless. easy right i don’t have to code anything i can just use excel spreadsheets… but my question is she dosent want to do it on a computer and wants to do it all on a tablet so i have no idea how to go about that?

Google docs has a spreadsheet. Check out https://www.google.com/sheets/about/
It should work with tablets