I understand that not all resources and activities are supported via Moodle Mobile2, but having followed the instructions here
https://docs.moodle.org/dev/Setting_up_your_development_environment_for_Moodle_Mobile_2
I tried to access a development version of Moodle 3.1, and although the mobile app logged me in, when I looked at any resource or activities such as file or page, it said they were not supported locally.
I then tried the Moodle demo site (http://school.demo.moodle.net), and again logged in fine but again was given the error message This activity or resource is not yet viewable in the app.
The environment is ionic serve or an Ubuntu workstation, and the install worked perfectly once I changed npm to 0.12.7. Browser is chromium (e.g. not running this from an actual app)
The actual Moodle mobile app works fine on http://school.demo.moodle.net, so there must be some error or config missing in the mobile app.