UPDATE:
I was initially quite impressed with Fuzen, but after diving more deeply into its architectural approach, I'm not so certain. I'm building a solution from scratch with a pretty detailed craft prompt. While the initial build looks good on the surface, it falls apart under the hood. Granted, the calculations and workflows in use are fairly intricate, but the issue is simple data flow from page to page. I've tried several times to get the tool to embrace the concept of global calculations and variables to use throughout, but it continues to generate code to recalculate on each page. So the issue becomes correct values on one page, incorrect or missing data on others for the exact same data. It also tends to generate mock code, calling it fully implemented. When requested to test, it will essentially fabricate results, and even though the actual and expected results don't match, it will denote test cases as passed. The other issue I've seen is relative to security vulnerabilities (I.e. storing app keys in the browser rather than server side). The cost of resolving the architectural missteps has far outweighed the speed with which fuzen can spin up a working solution. I do realize that the niche and complexity of my project may push the limits of what the tool is capable of, but the default architectural/security gaps noticed seem to be a bigger issue with the potential to affect other builds, not just my own. Also notice the AI overstepping my requests by proceeding with implementation of steps I explicitly stated not to make or to await approval before implementing. I'm torn on whether keep fuzen, hoping it will improve, or throw in the towel. After three failed attempts and exhausted credits trying to shore up the porous infrastructure generated, I'm deducting two stars.

Original Review:
Chose fuzen to essentially build out a few app ideas I've had floating around for a while. I'm crafting a calendar journal of sorts from scratch that will eventually be shared to my broader community. The build process was initially a bit of a learning curve, but I've adapted quickly. You really want to start with a very detailed craft prompt. I was able to get a working iteration up in no time; less than an hour. The challenge has been working through a few more complex mathematical and celestial calculations. No fault of the tool, just complex mathematical things based on planetary and geographical positioning/alignments. Overall I'm impressed with Fuzen, its been up for the task of creating something a bit unconventional. The tool makes coding a breeze. And as a former engineer, I love that I can go behind the scenes when necessary to do some more custom things.
I went with the highest tier, because I love that the credits refresh for life; which means I'll have more than enough credits to flesh out all of my ideas at least to some degree. I also love that hosting and all of the backend details are handled by the tool, so I don't have to worry about it. The credit usage is extremely fair and the AI is really fast and accurately responsive. The only thing missing, if I had to pick something I would like to have, is the ability to export/sync the code to GitHub, just to be able to maintain my own code backup in the event something were to happen to the tool. But overall I'm more than happy with my purchase. And I'm looking forward to all that I will have the ability to create. Thank you to the Fuzen team for this offering!