Teachable does have an app available to iOS devices that can be downloaded, however, TBM team does not actively promote the app or guarantee the functionality.
As of 2020, Teachable has made us aware that they are not currently prioritizing the development or improvement of their app, and that their main focus is the web browser experience. We recommend using a web browser, and Google Chrome, for best results on the Teachable platform.
This being said, the Teachable app is still available and you are welcome to give it a shot. We do have a number of members who use the app without any issues, however, due to the high number of bugs reported from our community, we are not confidently or relying on it, or recommending it to new members.