The first hidden gem in Delphi XE5 Update 2 is the Mobile Preview. It is not that hidden, and in fact is is documented on docwiki.embarcadero.com/RADStudio/XE5/en/Mobile_Preview. The goal of this preview is to let you compile and test and debug mobile applications on Windows (with a much faster compile/debug cycle than the actual mobile or simulator platforms).
Although in past versions of Delphi you could already add a Win32 target to a mobile target, and you could test the application logic, the user interface was really windows centric, looking ugly, and hard to test at all. The difference now is you get a look and feel similar to the actual mobile platforms, thanks to a specific FireMonkey style. Here is an example of a simple application with a few buttons at desing time and runtime on Windows:
For all Delphi mobile developers, this is a great addition, as it really helps trimming development time. Notice, though, that this is a preview, not a simulator or emulator, so you cannot interact with any physical device sensor, for example, or rotate the preview, or anything in that league. Also, this preview is intended for development only, not as a way to deploy mobile-like apps to Windows.
How do you enable the mobile preview for new applications? Simply add a Win32 target to a Delphi mobile application. What if you already have a Delphi mobile application (created before update 2) and add or rebuild the Win32 target? You'lll get the old effect with no style. That's because the preview is triggered by the inclusion of a new unit at the project source level (FMX.MobilePreview), a unit you have to manually add to existing projects, like I've done below:
PS: There was never a better time to buy Delphi, migrate your old Windows applications, and get started on mobile development: www.embarcadero.com/radoffer!