Someone suggested using an apple cutter to cut a potato. I thought to myself "this is a great idea." Soon I would find out that this is easier said than done.
I got my potato and my apple slicer. Now is where you need that 3rd hand. An apple has a flat bottom, so it stands for you while you slice. Potatoes, no flat bottom. It was super hard to get the potato still so that you could apply pressure on the cutter. Once you do, you can push hard and slice the potato. Be careful not to slice your finger in the process.
You do get nice uniform fries once you get through the cutting process. The middle fry is a bit wonky so you will need to cut it in half.
Overall, it is easier just to cut them with a knife.