Best apps and roms for Nexus 7?

Hey all you fine folks at the Verge.

I just bought a Nexus 7 this week and am totally new to Android. I've been using iOS since 2008 (when the iPhone 3G was launched), but I know absolutely nothing about Android. So far I'm loving this new tablet and Google's own native apps are amazing on this thing. My question is, does anyone know or recommend some great apps to get me going and maybe recommend some custom roms that I may try? I've already done research on how to unlock and root the device using Nexus Root Toolkit, but I don't know what to do with this amazing tablet afterwards. I still love my iPhone and iOS, but it's awesome to finally dive into Android waters. Any help would be deeply appreciated. Thanks. :)

And Happy Easter. :)

Dirk,

Toronto, Canada.