You might read this recent post Yavin ...
https://groups.google.com/forum/#!category-topic/mitappinventortest/hO3E7uYNbAA
ios using App Inventor 2 is still in testing, so how long will it take? I would plan on second quarter or third quarter 2019. It will be ready when it is ready.
Until then, consider using one of the commercial versions of App Inventor Block compilers... one of them can be used supposedly with ios now. Also note, the latest third party compilers are not completely compatible with App Inventor 2 aia Project files and vice versa. If you change compilers, stay with one...they are not totally interchangeable as they use different components.
Please be aware, all the current functionality available in App Inventor 2 for Android will not be available in the ios version for technical reasons...be sure to plan that what you programmed currently
might not be possible with ios.
Regards,
Steve