I like the overall flow of the website, the steps are easy to follow. That being said, the vectorization part was a bit confusing, and losing a bit of details wasn't ideal.
Consider adding more information for the vectorization step. I liked the tour though.
I tried it in my trusty iPhone 7. All logo creation steps worked and the UI was responsive enough, but I couldn’t open the Advanced options in the vectorization step.
I was a bit confused in the vectorization step as there are a lot of elements that can be edited, consider using Color palettes to make easier for the user.