Taxi App - Dev Changes

We have a taxi app built on below Tech Stack, we want to make some amendments and additional functionalities to the code
Looking skilled partner to assist in fixing some bugs and with good experience on the below stack

TECHNOLOGIES, FRAMEWORKS & DATABASE
iOS: Swift 5, Xcode 11.4.1
Android: Android Studios 3.0, and Java 8
Landing Page and Forms: Twitter Bootstrap, Ruby on Rails, MySQL
Backend: Ruby on Rails, MySQL
Admin Panel: Twitter Bootstrap, Ruby on Rails, MySQL
APIs: Ruby on Rails, MySQL
Hosting: AWS