The app is a bit buggy and features are relatively sparse, but it is intuitive to use and I can see the promise.
Within 20 minutes, I had an API structure fairly well plotted out, along with REST endpoints, a GraphQL schema and playground, documentation, and places to add webhooks (although no way to programmatically add webhooks easily, as far as I could see).
I may be over-rating this simply because it comes at a good time for me - I recently spent hours reading through the JSON:API specification [0], and trying to figure out how it is different to the OpenAPI specification [1], and how to actually get into implementation, and generally getting bogged down in levels of detail that I never knew existed.
The only fear I have with this service is that the pricing structure will be too high. I would be keen on a usage-based pricing model based on amount of data stored, with a free tier for personal projects. This would allow me to play around with it myself for free, while internal business tools with higher usage would be paid.
Interested in talking about what pricing may turn out to be - if you want to get in touch, my email address is on a feature request I submitted about adding a datetime field.
(edit to remove extraneous character, in the process adding lots more extraneous characters)
[0] https://jsonapi.org/format/ [1] https://swagger.io/specification