React app polish + backend + store launch (Google Play & App Store)

I have a working React app (3–4k LOC) generated with AI. It’s already functional (profiles, projects, image uploads, location search), but it needs production hardening, UX polish, and a real backend for roles/permissions… (Budget: $250 – $750 USD, Jobs: HTML5, JavaScript, jQuery, jQuery / Prototype, Mobile App Development, MySQL, PhoneGap, PHP)