Hi,
My name is Rodrigo and I'm a Software Systems Engineer with more than 7 years of experience in building software as well as Project management.
I do not currently have something like you are asking, but If you agree to work with me I can have a prototype ready in around 10 days.
If you fiel good about the demo, we can go on and finish the Project. Else, you can go to any other provider and take whatever work I developer.
Costo for the demo would be 500 USD, BUT YOU ONLY PAY 250 at the start, and the other 250 If you decide to continue working on the Project with me. At the end of the Project you pay the rest.
I hope my offer is appealing and we can work together soon