iOS support is no longer on the roadmap for a number of reasons.
The biggest reason being an Apple App Store policy being enforced that does not allow apps on the App Store akin to 3rd party Tesla apps, such as Dashboard for Tesla. You can read more information on the policy change and its affect here:
Another reason is due to the lack of support for background services on the iOS platform. A lot of the great exclusive features Dashboard for Tesla has require a scheduled background service to run without the app being open in the foreground, such as plug-in reminders, Smart Charging, Automatic Behaviors, Smart Charging, etc. These features are not supported on iOS due to the restrictions on background services, these would only be able to run if the app were open in the foreground which greatly hinders convenience of these features in the first place.
There is a way to support these features on iOS by moving all background services onto a remote web service that's always online, however this introduces operating costs and security concerns outside the scope of the app.
For the time being, iOS support is indefinitely suspended, but I will update this should that change.