Develop a .Net app that will be used across multiple platforms

Small app that will work with multiple online web services to share and store data. App will be written in .Net and Xamarin/Mono will be used to deploy across other platforms. Applicants should be highly capable in C Sharp and visual studio, experience in 3rd party APIs and restful services (consuming). UI development is also a plus though we may use another developer if necessary. The project has a 3-6 week timeline but depending on how things work out it could extend into other apps and features Will oversee development and deployment of new release in Xamarin, existing app was built in Java. Instrumental in all areas of developement and decision making "best practices" Depending on .NET experience and skillset could become fulltime position. Right now looking for multiple positions and deciding on whether our Xamarin expert could also fill other postions vital to our business. Working on a short timeline and hope to make decision very soon to meet deadlines based on marketing plan but development takes priority, we are looking for a good product above all else. We have a loyal dealer base and make customer satisfaction a benchmark of our business.