Just experienced I try what inspire and make monochrome Classics. changed my mind or remember that I can change the ISO manual, yeah it not iPhone.
I’ve forget skill what I have experiencing it photo shoot a long time with iPhoneography. Selecting ISO and adding grain are important for black and white photos for imagination of raw.
So, just exsample I’d shoot with ISO12800 of Fuji x100. 
just RAW. 
Featured grain. 
Final edited.
Mono x Tone 