I've been trying to set up the Gramps web app but it's not very promising. The first problem is that Gramps doesn't follow Python common practices. I was surprised to find Gramps uses autoconf and make instead setuptools. The Gramp web app uses Django but if you run the usual command python manage.py runserver, it doesn't work unless you also set the PYTHONPATH environment variable to point into the source tree. Granted, the correct command is executed when you do make run, but why obfuscate things for someone who knows Django?
Anyway I did get the web app to run, but only after I modified the hard coded default locale setting, since I don't have en_US.UTF8 installed on the system. However I still can't login because the Django cross site scripting code complains that the cookie has not been set.
At this point, I gave up for the time being. My impression is that the Gramps web app is not quite ready for prime time. I was going to suggest you look at the web app demo site, but it was down at the time I wrote this.