Cannot find and remove/delete the first Navigation Bar which is showing up on mobile application.
The name of the Navigation Bar is 'Application' and it contains sections called 'Service Catalog' and 'Field Service'.
Release or Environment
The Application Nav Tab and the Sections are coming from Mobile Applications table sys_sg_application table.
This is an OOB table which comes from the Mobile Plugin.
To resolve the issue perform the below steps:
1) Log in to the instance from platform.
2) Go to https://instance_name.service-now.com/sys_sg_application_list.do
3) Set Service Catalog and Field Service records to false.
4) Log out and login back to the mobile app.
Now the Navigation Tab Application should not show up anymore on the mobile app.