Twister boards can help with balance and core strength. A simple core workout on the sela twist board is to stand on it, bend knees slightly, and twist torso about 45 degrees to one side, hold for up to 10 seconds, and return to front facing, then repeat with other side. The deeper you squat the more you will feel the burn. This is simple to use, twists easily, and can be a great beginner workout.
This is also easy to store/hide when not in use. I personally slide it under my couch, as I normally workout in my living room, so it makes it easy to hide away quickly, and to get out when I am ready to use it.
You can purchase on Amazon for $19.99