[laurent]

I can't talk for the other people so I don't know how they are going to use .abc with Mobilesheets.

I used to have all my tunes in one file, in order to be able to re-use the common abc instructions, but when I imported into Mobilesheets, it made more sense to me to separate them, so that's what I did.
I wouldn't mind personally that you index the first song of each file, if you want to incentivize users to keep their .abc collection in a Mobilesheets friendly way.

I suppose that ideally, you would index all tunes in Mobilesheets and clicking on any of them would get you to the correct file and page, just like a link to an HTML page that has a # anchor, but I don't know if that's even possible.

I understand that probably not a lot of users are using .abc right now.
I was interested in .abc support for a long time actually, and I only discovered it was supported for standalone .abc files last month, so I suppose the word is not spread even for Mobilesheets Pro users.
I have to admit I don't read all the details in the release notes...

I just sent an email to the maintainer of https://abcnotation.com/software#mobile to ask him to add Mobilesheets to the list of apps supporting abc. You haven't implemented playback yet, is that correct?