Appium Exploration Project

I would like to write a very simple native app (Android or iPhone is fine) that actually shows a couple of screens one has 10 buttons and some operations as a calculator and the other screen shows the result of the process... I want to use Appium to test automate the app... I want someone to build the app and then develop the test automation using this framework and walk me through the steps and the process. The timelines are short and I would like it done within the coming 72 hours. Thanks.