It has the added benefit of being integrated with the system dictionary, so if you add any extra dictionaries to the system, such as foreign languages, they will also be immediately supported in Kotoba.
Unfortunately: "App Store guidelines disallow using the built-in system dictionary to create a dictionary app"
That's too bad. I wish there was an alternative App Store version that used another dictionary because I really like its design choices. At least I did, when I tried it on my iPhone, but I don't imagine they had drastic changes since then. I didn't stick with it because of weird limitations Apple has with sideloading apps. (IIRC, that 7 day limit was the deal breaker.)
It has the added benefit of being integrated with the system dictionary, so if you add any extra dictionaries to the system, such as foreign languages, they will also be immediately supported in Kotoba.
Unfortunately: "App Store guidelines disallow using the built-in system dictionary to create a dictionary app"
Write up on daring fireball here: https://daringfireball.net/linked/2018/06/19/kotoba