You should know that by using Materia, you have agreed to it's EULA that explicitly says that you cannot create any similar product in terms of look and functionality.

"Copy any features, functions or user interfaces of the Products;"

https://getmateria.com/terms

So now it becomes much harder for you to make a similar product.

Can such an EULA even be remotely binding? Especially in the light of the fact that the OP notes that he had independently developed a very similar product, and there are a lot of ? What is so unique in this product that similar features in another application could be proven to be copying?

It would depend on where the EULA was accepted and which country the developer is from. If it's the US, I bet the person with the deepest pockets would win in court (or settle). If it's in the EU, there are already a ton of patents about visually binding SQL - the biggest being Oracle.

Wow, that's weird