GameEx is very customizable and user-friendly. There's a ton of themes available, not to mention plugins, snapshot and video packs, batch scripts, custom emulator backgrounds and icons... It's almost a little overwhelming when you think about all the cool stuff GameEx can do for you!
Think of this portal as a place where you can go for assistance in customizing your cab or MCE to fit your needs. Just click on a tab to get started!
Contributions can be posted in the GameEx forum or emailed to the ConfigHQ. Features of the GameExtras portal include:

.: USER THEMES :.
A common way to customize your copy of GameEx is to change up the theme to fit your cab. Forum members (such as Amos_82) are checking in frequently with new contributions.
For instant access to the latest themes, click here. To check and see if your theme has recieved an update, click here.

.: IMAGES & SNAPS :.
GameEx can utilize GoodMerge support. To help make the GoodMerge feature truly something great, you can download screenshot packs with archive-specific naming. For example, instead of having the usual GoodName snapshot: Super Mario World (U) [!].png these packs have been named specifically for this feature: Super Mario World.png This takes all the guesswork out and promises a complete set of snapshots for that system. Boxart and cart scans will also be available here.
You will also be able to download MAME and emulator GameEx UI icon sets and other misc. GameEx artwork in this section.

.: EXTRAS & TOOLS :.
There's a new plugin system for GameEx! User contributions will be located here. You will also be able to find LingPanda's Captivate Tutorials if you're in need of setup assistance. You'll also find various other tools, like Headkaze's PleasureExtractor or Nologic's auto scripts and auto-renamers, WinKawaks setups, user-contributed databases for emulators... Basically anything else you might find a need for.