Sorry, no iOS. We do have an Android app. This can also be used to access this forum too, though the functionality differs from device to device (on some devices three options SC / forum/ voice show up, while on others one needs to navigate).
Another option for accessing this forum (not SC) is the Discourse android app.
SuttaCentral uses PWA. I had earlier created a PWA android app which later metamorphosed into the (un)official Google playstore app.
An iOS app for SuttaCentral can be created easily using the same kind of process. Submission to the app store will however require someone with an Apple developer account and Ven @sujato 's permission. Any volunteers? 