Build a custom shopify app

Hi, I'm in need of a custom app for my shopify store that allows me to make my local delivery option exactly what I need. In short I've tried the existing shopify apps, and I can't get exactly what I want out of them. What I need: Control local delivery options with shipping zones set by zip code (exact match) Offering one hour delivery, and selectable two hour delivery windows Limit number of deliveries per shipping window One hour delivery shipping option only offered during delivery hours Free shipping at X price Zip code check before moving through check out code to allow zip code check elsewhere in shopify store Easy/Intuitive to use