I would like to hire an App Developer

What we need is a bottom up re-write of the app. It should look great and provide the user the necessary screens to subscribe and pay for our service. These can be a single page webapp if necessary, or screens running on the device. Once subscribed, the app should run as a background service, logging onto the system at start-up and/or when there is internet connection. The app should hold open a socket connection waiting for instructions from our server. Most of the time the app is idle and therefore, steps must be put in place to prevent the OS from stopping the app. When the server ‘pushes’ a command to the app, the app will generally either display a message, play an audio stream and/or display an image. At the end of the ‘broadcast’ the app must be able to detect the stream has finished, without error. In some instances a message from the server will instruct the app to stop playing the stream, but not always, sometimes the stream may simply disappear. If the app loses internet connection and subsequently regains connection, the user is logged in seamlessly without any interaction. The app should be written in c# using Xamarin for Visual Studio (and if a webapp is used, asp.net on IIS) and compiled against Android, IOS, UWP and Windows phone in that order of release/priority. IP and copyright must remain with ourselves at all times. Deliverables would be when our testing/marketing team have approved the app, and our development team are able to compile your code independently. If this is something you can help us with, I would be happy to meet with you to thrash out a specification and to introduce you to the APIs in order to interact with our streaming servers.