Most people have probably already seen this but in case you missed it in September 2013 Embarcadero released a set of premium styles for Delphi XE5. The styles come in two colors which are Jet and Diamond. There is a style included for each of the supported OSes which are Android, IOS, OSX, and Windows. What I do with my mobile apps is put a TStyleBook on the form, assign it to the form StyleBook property, double click it to bring up the style editor, and then pick the style for the OS that I am currently compiling against. You can also do it via code but for testing purposes this was the fastest way for me. Apparently the Firemonkey styles have support for the different resolutions provided by devices with Retina resolution displays. The style pack should really just come with Delphi XE5 when you install it but maybe it will be integrated with the next version.
Premium Styles For Delphi XE5 Firemonkey On Android, IOS, OSX, And Windows by Delphi XE5 XE6 XE7 XE8 10 Seattle Berlin Tokyo Firemonkey, Delphi Android, Delphi IOS is licensed under a Creative Commons Attribution 4.0 International License.