Mobile App(Android/IOS) for an existing C# Web Application

I have an existing web application that I would like to also collect data using mobile with a user friendly interface the mobile version of this data collection tool must allow to collect data offline as well and submit to an sql when there is a connection.

I will provide the interface wireframes I have created and access to the existing app and explain in detail the backend. A lot of REMOTE work will be needed we can discuss more with those interested. Thank you