Comprehensive Bike Garage Customer App

I need a single, integrated mobile app for my customer that lets my bike-garage business run every daily task from one screen. Should Build a Dynamic Vehicle Diagnostic Funnel & Valuation Wizard like (https://sabkophone.com/sell-your-phone/)... (Budget: $250 - $750 USD, Jobs: Android, API Development, Cloud Computing, Flutter, iPhone, Mobile App Development, PHP, React Native, User Interface / IA)