Wow. Congrats on launching your first product on PH! That's a huge achievement.
I absolutely love this. It reminds me of my first year as a PM and using Balsamiq to create the simplist of wireframes. This is way better and as easy.
One quick feedback: I noticed that when I clicked on "Library" to create my own, all of the components' previews didn't show up. Wasn't sure if that was intentional but being able to see roughly what it looks like before adding it to the page would be tremendously helpful.
Overall, well done on building this man!