User roles determine the permission status, and thus determine if they will be able to see the prices on the job.
If you want to hide pricing, you will need to create or change the user role a "Crew Lead" or "Crew".
Roles can be selected and changed in the web app.
After you login then:
1. Click on the "Users" Tab.
2. Click on user's email (or use the search function to find them).
3. Select the users role and change to "Crew Lead" or "Crew"
Now, when they login to the mobile app they will not see any prices.