Since the onset of smartphones, we at Diamond Software have specialized in GPL location tracking. We have written four major products in this venue. Two of them, Intelligent Reminder and Sunriver Navigator, can be found at the Play Store. The other two, Commuter Alert and KidMinder are at beta level ... but we're happy to send them to you if you'd like.
The point is, we are very experienced in this arena, feel qualified to be a candidate for your app. Please have a look at our bio, as well. You'll see that Diamond Software (known as Budget Software back in the 80's and 90's) has been freelancing computer software since 1985. Our software was bundled with Borland's Quattro Pro, and we were invited to IBM's Research and Development facility in North Carolina to demonstrate complimentary software to their Visual Age for Smalltalk.
In short, we write reliable software, and we are trustworthy.
Please give us your serious consideration.
Mike Samuels
President, Diamond Software.