Hi.
I saw your description carefully and I am confident I can full fill your requirement.
So I provide my skills in hopes of working with you.
I am full-stack developer and I have 3+ years of ample experience in the iOS(iPhone, iPad) & Android app development.
-Android(Java/Kotlin)
-PHP(MySQL), NodeJS, ExpressJS, MongoDB, Google Firebase, Amazon Web Service
-Integration: RESTful APIs, Payment Gateway, Google Map API
-In-App purchase & push notification & Approval to AppStore
Please feel free to contact me if you want.
I look forward to working back with you.
Thank you!