Writing a mobile application for Android

The task: to write an application, for starters, for smartphones and tablets on Android, which will find out its location using the Yandex API (or take it from the built-in GPS), compare it with the coordinates I set and give the time of the owner of this smartphone in the specified area to our server. At the same time, it is not necessary to transfer data if the person is not in the zone of the specified coordinates. Also, you need to filter out characters who are in the specified area less or more than the specified time, data about them also do not need to be transferred. The result should be a working application and its source code.

Here's the API description:
http://habrahabr.ru/company/yandex/blog/162955//
http://clubs.ya.ru/company/replies.xml?item_no=34348

If successful, orders will follow for the transfer of this application to other mobile platforms.

Gradual payment, technical task agreed.