Your idea of a smartphone app that runs on iOS and Android will be materialized professionally using React Native which is a leading industry-standard technology.

I will develop your app myself from scratch to end, I will liaise with you on every stage to make sure that the app meets your requirements. Do not worry about the quality of your app as I like to do things as perfect as possible, and I surely have the capacity with 3+ years of experience in React Native.

Please note that an Apple Developers Account is required and I will need to be added to it for an iOS build of the app. If you have any more questions then please send a message my way and I'll reply as soon as possible.

BONUS: 

I offer lifetime maintenance of applications that I develop regardless of your app is a day or a year old :)