I decided to test out ProjectShapeshifter. As a customizable app, I would rate its ease of use as a 5. Very user-friendly and intuitive. The flexible parts are on the right side, and your artboard in the middle. The problems I see in this app are its constraints. There are clear limitations a user can see when first using the app. For the most part, most of the shapes you can make are only geometric. Organic forms are not possible. I give it a 4 for customization. Still, the user can change the number of faces and create complex geometry.