Thanks.
One question: can you change/handle the gain with this app?
Good question - I just checked.
The app has undergone some changes during the 4 years I have used it.
It seems like gain can be changed with "foreign" mics on my old iPhone 5S, but not with the latest version of the Motiv app running on my iPhone 8.
So the answer is probably that this app it is not for you - unless I am overlooking something obvious.
Sorry about the confusion.