Here is another portable workout device that lets you work your core at home. The Ab Blaster is designed to give you a complete core workout. It targets your abs 180 degrees. Just place the base plate under a door or piece of furniture, lock your feet in place, adjust the foot plate to the left or right up to 90 degrees, and you are ready to go. You can clearly see the angle on the device.
The Ab Blaster is currently getting funded on Kickstarter.