Apex Launcher (free and paid version)
Some owners are unhappy at the inability to display the home screen in landscape orientation. Apex Launcher is a replacement launcher that allows screen rotation and so much more.
Here's the home screen rotated into landscape thanks to Apex Launcher.
Fancy Widgets and standard Jelly Bean Home Screen
This is the standard Nexus 7 Jelly Bean home screen. The weather/clock widget is Fancy Widgets.
Ultimate Rotation (7-day free trial available)
For those who don't want to root the Nexus 7 or even install a replacement launcher, Ultimate Rotation allows rotating the home screen (and other functions) using the standard Nexus 7 Jelly Bean launcher.
Here's the last home screen rotated into landscape.
I am a heavy Evernote user and the app works well on the Nexus 7. The most recent version takes full advantage of the larger tablet display with sliding panes as demonstrated in this screen.
Plume (free and paid version)
I am a heavy Twitter user and Plume is my preferred method to interact with the social network on the Nexus 7.
The app displays a single column timeline in portrait, but when you rotate into landscape it presents three columns of the user's choosing.
Flipboard only recently was released for Android, and it is great to use on the Nexus 7.
Keep up with news and your social networks in one interface that looks spectacular on the Nexus 7 screen.
I confess I use Google + far more now that I have this app on the Nexus 7 than I ever did before.
It presents the updates from the people I follow in an outstanding graphical way that works fluidly on the Nexus 7.
I follow hundreds of RSS feeds, and gReader Pro is my favorite way to do that on the Nexus 7.
It uses a multiple pane configuration that really shines in landscape orientation, while still working well in portrait.
Google Play Music
This music player is preinstalled on the Nexus 7 and is a solid app for those with music collections.
You can play music stored locally on the Nexus 7, or stream your tunes from the Google cloud. It's your choice.