That would require DECA to make the app though.
You used to be able to use Muledump to register daily logins but AFAIK that’s no longer possible, and even if it were running Muledump on your phone is far from trivial.
So that, and definitely else such as crafting (using the Forge in RotMG I guess), would only be possible with a companion app. And I can’t ever see them doing that.
If DECA do anything I would think it would be full port of the game, which in many ways would be easier; Unity supports exporting to iOS, and having just one app to support is less hassle. It would certainly be more worthwhile, giving people more ways to play and enticing new people to play it.
The one argument against it is RotMG is not a very good Unity game. I like the game, or I would not be here. But it has horrible performance, suffers from disconnects, other bugs. Chances are it would perform even worse on most phones and tablets. It might even be too poor for Apple to approve it.