Developer Xavier Martinez Garsaball has a component for Delphi XE6 Firemonkey called Google Maps Library (GMLib) which wraps the Google Maps API and implements it in a web browser control. For Windows this means it uses TChromiumFMX but it is built in such a way as to allow another web browser component to be substituted in it needed. In addition to Firemonkey it also supports VCL and would probably compile under AppMethod as a desktop project. I don’t think it supports Android or IOS at this time but since it is open source you could probably get that working if needed. If you need mobile support check out WebGMaps from TMS Software. Here are the layers that the library supports from the Google Maps API: Bicycling, Panoramio, Traffic, Transit, and Weather. There is so much functionality packed into this library that it is difficult to list it all here. For example, here is the list of classes from the library: TGMMap class
TGroundOverlay class Head over and check out the extensive documentation before downloading the Google Maps Library for Firemonkey source code.
FMXExpress.com has over 700 tips and tricks for building cross platform apps on Android, IOS, OSX, Windows, and Linux with a single codebase and single UI using the FireMonkey framework found in Delphi and C++Builder.
FMXExpress covers top cross platform secrets for FireMonkey in C++Builder and Delphi XE5, XE6, XE7, XE8, Seattle, Berlin, Tokyo, Rio, and Sydney.