"Thumb scroll" feature in grocery shopping lists

I'm using the "Reachability" feature on my iPhone quite often as I find it convenient to bring buttons to the bottom of the screen when they would otherwise only be reachable using your other hand or changing the way you hold your phone in the hand. So on that topic seeing the "Thumbista" concept I thought it would be fun to make a grocery shopping list that shrinks to the bottom right side of the screen when needed.

The "One hand" button on the bottom right corner of the "Standard list view" interface leads the user to the "Thumb scroll view", where they are able to scroll items and tick/untick them all using only vertical swipes of the thumb. Users then have the ability to return to the list view using the "Two hands" button on the bottom left portion of the one hand view.

Are there any great apps which use similar features? I'd be interested to try them out!