There are a few options to access reports in the Salesforce1 mobile app. Let's discuss them in detail.
Before the spring 2015 release, the Reports menu item was not available. If you cannot see the Reports menu in the Salesforce 1 app menu, make sure you add the Reports menu. Navigate to Setup | Mobile Administration | Mobile Navigation, select Reports, and add it to the selected items.
When you open a report in the Salesforce1 mobile app, the report format will be ignored. The summary and matrix reports data are presented in columns, with each summary field being in its own column. You can sort the report by tapping on the header of a column. By default, this will sort the report with that column in ascending order, tap the header again to sort in descending order.