Sadly, this is the only iOS app with Calckey support. And it’s not great at it either.
Not only is it slow, mostly unresponsive, and generally unintuitive to use compared to it’s web counterparts, it also lacks some core features. (renoting without having to quote, like button, dm/gdm support, like button along with the react instead of replacing)
At this point, you are better off using the website on your phone. Keep it bookmarked or whatever. Just don’t use this.