I dont find the Approval tab in the Salesforce1 app. However when viewed on my desktop browser (https://.salesforce.com/one/one.app) I see the Approval tab. Is this a bug or some sort of limitation of Salesforce1 app? Both cases it is the same user login so its not a user rights issue.
I am posting screenshots from the mobile, as well as from the browser below.
Adding setup screenshot from Setup->Mobile Navigation