I stumbled across this app when I was searching for a writing app I can use for academic writing. It was probably designed for any form of long-form writing, particularly for writing novels. The developers own website for Ahti is at:
https://www.bretmerritt.com/#ahti

As you can see from the screenshots, it will be very familiar to Scrivener users. Which is just perfect for me. I find I work well in writing apps that have a binder layout and text void of markdown symbols. I do not know why I am wired this way, I just am.

Ahti is a simpler, more modern, version of Scrivener that many folks have been after. Not only does the interface provide a clam and clean place to write in, but the app also has versions for the Mac, iPad and iPhone. Of particular importance to me was that it syncs between devices using iCloud. (No more being forced to use Dropbox to sync with iOS devices, at last!)

Files are stored in plan text in .md format, which was surprising to discover. So you have the security of knowing you have the manuscripts in a format that can be used widely should the app ever disappear.

In the first day of putting Ahti to use, I have found it be lightning fast. The only time I found it a little sluggish was when I was opening an existing manuscript on another Mac or iOS device for the first time. This maybe more an issue with how iCloud works than a problem with the app. I have found when I open the same manuscript the second time onwards it is very snappy. At the moment, it doesn't seem to be able to save pdfs nor images. I have yet to make contact with the developer, but when I do I will ask whether this is on the radar in future development.

I haven't been able to find a trial for the app, but it so cheap that this wasn't an issue at all. Even with the Japanese yen at the lowest it has been in close to 40 years, the price is about a the same price you pay for fancy coffees these days. On the Japanese Mac App Store it is priced at ¥1,000 which gets you all versions of the app. The price in US dollars is $5.99. The link in the Mac App Store is:
https://apps.apple.com/us/app/ahti/id6781643515?platform=mac

Looking at the developers website, it appears that Brett is "senior frontend engineer". I don't really know what this means, but he seems to know something or two about computing and programming. I am scratching me head trying to work out how he was able to develop the almost perfect writing app. ;)

By the way, MojoPad has now become my daily goto app. It has become my "thought studio". I see Ahti being my go to app when I need a dedicated place to just write and complete a research paper, whether that be on the Mac or on the iPad, or, when inspiration hits and can't wait, the iPhone.