Report in Salesforce mobile app

Since Spring '15 release, with Salesforce1 app version 7.1 and above, you can access Reports from Salesforce1 mobile app, in earlier version, you only have option to drill-down to report from dashboard.

From app version 7.1, you can access your most recently viewed reports right from the Salesforce1 navigation menu. You also still can access other reports by drill down from a dashboard.

If you do not see Reports menu, as system admin, you can configure it from Setup | Mobile Administration | Mobile Navigation.

All reports are shown in tabular format, with groupings added as columns to the end of the report. For example, on a summary report grouped by Industry and Type, those fields appear as the last two columns of the report. Reports with the joined format are not shown.

The Smart Search Items will show all objects to Salesforce1 app. This item also adds a set of recently-searched objects to the Recent section and adds "Show More", so users can access all the objects they have permission to use and that are supported in Salesforce1. If you don’t include this item in the navigation menu, users can’t access any objects in Salesforce1. 

Anything you put below the Smart Search Items element will appear in the APPS section of the navigation menu.

Reference:

• Access Recent Reports from the Navigation Menu
• Customize the Salesforce1 Navigation Menu