Run 3 Android apps side-by-side on an HP TouchPad with Cornerstone

Cornerstone is a new framework for Google Android that allows you to run three Android apps at the same time — on the same screen. Now you can try it out on an HP TouchPad, thanks to an unofficial build of CyanogenMod 9 from xda-developers forum member antiphon.

There’s also an alternate version of CM9 with a skinned version of Cornerstone available from RootzWiki forum member Icefoot.

While Android has always supported multitasking, typically that’s meant apps could keep running in the background while you used a different one in the foreground. For instance you could listen to music while surfing the web at the same time.

Cornerstone changes that by dividing the Android user interface into three boxes – one main window and two smaller windows. You can run one Android app in each window.

By default, when Cornerstone is running you’ll just see a thin toolbar at the right side of the screen (or at the bottom of you’re in portrait orientation instead of landscape). Tap the toolbar and it will slide out, shrink the main window, and display the two smaller windows.

You can select which apps you want to load in the smaller windows at launch — but you can also access an app menu at any time to change those windows so that instead of viewing Facebook and News & Weather like you see in the picture above, you can access virtually any Android app.

But not all apps or features will work well in the unusually sized windows. Even apps such as Google Maps that do appear to run well in the little windows can cause some unusual actions. For instance, pop-up windows may display in the center of the screen instead of the center of the window.

And it’s not just the little windows that have unusual screen resolutions. When you slide out the toolbar from the side of the display, the big window on the left is resized as well — and many Android apps were designed for specific screen resolutions such as 1280 x 800 or 800 x 480 and won’t display properly in the resized windows.

Fortunately you can exit Cornerstone any time you like simply by tapping the X button.

The CyanogenMod team is considering building Cornerstone into the next release of its popular operating system based on Android 4.0 Ice Cream Sandwich.

But independent developers are already incorporating the open source Cornerstone framework into their own custom ROMs. Antiphon’s build is based on the latest public alpha of CyanogenMod 9 for the HP TouchPad and it has most of the features (and bugs) of the original. For instance, some users may have problems with WiFi, the camera doesn’t work, and there’s no hardware video acceleration.

You can install antiphon’s build the same way you would install CM9. If this is your first time installing Android on the TouchPad, follow our step-by-step instructions, using antiphon’s zip file instead of the default CyanogenMod build.

If you’ve already installed CM9 or another Android distribution and have ClockworkMod Recovery on your tablet, here’s how to try out the new build with Cornerstone:

1. Download the latest build from the link at the xda-developers forum or RootzWiki and copy the zip file to your TouchPad.
2. Press and hold the power button to shut down your tablet and either choose the option to reboot to recovery or shut down and then press the power button to restart.
3. From the Moboot menu, select the “boot ClockworkMod” option, using the volume keys to scroll up and down and the home button to select.
4. Optional (but highly recommended): Navigage to the backup and restore section and make a backup of your device so you can restore if you run into problems or don’t like Cornerstone. Then return to the home menu.
5. Choose the “install zip from sdcard” option in ClockworkMod.
6. On the next screen, select “choose zip from sdcard.”
7. Naviate to the folder with the zip file you downloaded in step one and select it.
8. On the next screen scroll down to select “yes.”
9. This will start the install process. When it’s done reboot your device and this time choose CyanogenMod from the boot menu.

Note that if you’ve installed a custom kernel you may have multiple options in the Moboot menu. For instance, I’ve installed the “Bricked Kernel” on my TouchPad — but Antiphon’s software doesn’t seem to like that kernel. I had to choose the option to “boot CyanogenMod” in order to get into Android 4.0 with Cornerstone.