Your idea of a smartphone app that runs on iOS and Android will be materialised professionally using React Native which is a leading industry-standard technology developed by Facebook.
I will develop your app myself from scratch to end, app store submission not included in the basic package, and 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.