I found it!!
Hard to find because the Android interface has changed a little since the video was done. It's at the bottom of Transposing Instrument (from the little Gear (Settings)) It's called 123(Number System)
Oops..I re-read the question - sorry for post that did not help the original...
I thought I just watched saw this feature in one of the Android videos - now I can't find it again -weird - I'll watch them all again tomorrow and post if I find it.