On Tue, Jan 31, 2017 at 3:56 AM Alan Schmitt <alan.schmitt@polytechnique.org> wrote:
On 2017-01-31 03:58, Sean Escriva <sean.escriva@gmail.com> writes:

> Hello fellow Org users,
>
> After beta testing several builds, the latest updated version of
> MobileOrg for iOS has finally been released:
> https://itunes.apple.com/us/app/mobileorg/id634225528?mt=8
>
> Functionality is essentially the same as the previous version, just
> refreshed the various SDKs and updated the Dropbox API due to Dropbox
> deprecating v1.
>
> Please report any bugs to Github: https://github.com/MobileOrg/mobileorg/issues
>
> Much thanks to Mario Martelli and Boris for their invaluable help
> getting this release ready.

Thanks a lot for this release. I just gave it a try and it works great.

I have a question about how to choose what to synchronize. Looking at
the documentation, it seems to be through the index.org file. I tried to
modify that file but everything is reset at the next org-mobile-push. So
I tried to set some variables like this:

(setq org-mobile-agendas nil)
(setq org-mobile-files nil)

and I still have a lot of agendas.

This is actually the behavior defined by org-mobile.el in the function org-mobile-push: http://orgmode.org/cgit.cgi/org-mode.git/tree/lisp/org-mobile.el#n306 
the actual file is created here: http://orgmode.org/cgit.cgi/org-mode.git/tree/lisp/org-mobile.el#n662 

Is it possible to configure org-mobile to have no agenda at all?

By default, not that I know of. 
Perhaps there's some way to advise org-mobile-create-sumo-agenda to do something different or essentially nothing, but I generally try to avoid that.
 

(My goal is to start adding things one by one as I need them, I have too
many org files, and too big agendas, to sync them all.)

Perhaps you could look at defining a function for org-mobile-pre-push-hook to empty zero out org-agenda-files, then restore the value in the post-push hook. I've never tried that though so I don't know how if it would really work or what side effects there could be.
http://orgmode.org/cgit.cgi/org-mode.git/tree/lisp/org-mobile.el#n202
 
Sean