I am doing mobile applications. For GPS, I usually use CoreLocation for iOS and Google Play Services for Android. Let me know if you need some other frameworks,
You mentioned 'polished' because it is pleasant to work with client who care about how the product looks like.
Which UI controls do you use?
In my practice, we used Telerik and ChocolateChip-UI.
I have performed various tests on games in Android and IOS by developing test plans and strategies and examining all aspects of the programme from a clients or end-user's perspective and finally finding and eliminating bugs and any other problems.
I do not see any problems to work with any other frameworks.
I am self-disciplined and track all tasks and spent into excel spreadsheet. I agree with your payment conditions and would like to work in this project.