If I remember right, OBD Fusion on the app store could show boost. I used that with a Carista dongle.
Most, if not all of those apps are generic OBD, not VAG specific PIDs. OBD11 might show actual and requested though.
I gave up on those apps and use VCDS mobile instead.
Just need to figure out an iOS automation to disable the auto screen lock whilst it's running though.
One thing I did notice with OBD Fusion is the phone got bloody hot from running that for 20 mins or so. Not sure if all apps do that, but VCDS mobile doesn't.