Blocks cannot be viewed on the mobile app.
If the content is html then you can for example use the page resource. Or you can write your own module, but adding it to the mobile app requires you to develop a web service in the module and create a downloadable mobile app add in. Not trivial. Sorry, but I am on a phone and can't point you to the documentation.
https://docs.moodle.org/dev/Moodle_Mobile_Remote_add-ons is the link you need for the remote add on.
If you are running an older version of Moodle than 3.1 you need to enable the latest features of moodle mobile with this plugin. https://moodle.org/plugins/local_mobile
Thanks for your reply Mr. Brian