How to report Salesforce1 mobile app usage?

So, you just roll-out Salesforce1 for your company internal usage, next step is to monitor your user usage and present it to management for user adoption.

You can download Login History into CSV file and using Ms Excel to filter Application containSalesforce1, but it is pretty complex and you management cannot run it as Salesforce report.

Using Custom Report Type
Start with create a new custom report type:
•  From Setup, click Create | Report Types
•  Click New Custom Report Type button
•  Enter the following values.
   •  Primary Object: Users
   •  Report Type Label: A unique label such as Identity Users
   •  Report Type Name: This field automatically uses the label; change it if you want
   •  Description: Give it a useful description others might see.
   •  Store in Category: Pick a category for this report; such as Administrative Reports.
   •  Deployment Status: Keep as In Development until ready to deploy this report for other users. 
•  Click Next
•  Select Click to relate to another object
•  Select Identity Event Logs (Users)
•  Keep A to B Relationship to default "Each "A" record must have at least one related "B" record"

•  Click Save.

Continue with create a custom report:

•  Click the Reports tab and New Report
•  In Administrative Reports, select Identity Users and Click Create.
•  Drag-and-drop fields on to the report. Some useful fields to add into report: Full Name, App: Connected App Name, Timestamp, Status and Usage Type
•  Add Filter “App: Connected App Name contains Salesforce1”
•  Give the report a name, such as: Salesforce1 Usage.
•  Click Save
As this is a normal report, you can adjust the Time Frame.

Here is the screenshot of the report created:

If you see above report, in Usage Type:
•  OAuth Authorization: when the user first logs in
•  OAuth Token Exchange: when user has been idle for some time and the app needs to re-authenticate
In the Status, Error: App access denied tell you if user hit "Deny" in Salesforce1 app

Another example of report below, App: Connected App Name tell you each transaction of login attempt or re-authenticate attempt from Salesforce1 app from iOS or Android devices.

Using the "Power of One", you can easily count how many users login to Salesforce1 app from iOS and Android device, then add a simple chart to the report. In sample below, it show number users for Android = 34 and iOS = 276, with total of 305 users. This mean 29 (34 - 5) users using Android only, 271 (276 - 5) users on iOS only and 5 users are using both Android and iOS devices to access Salesforce1.

If you need to do further analysis, you can download the CSV file and use Pivot Table in Ms Excel.

Anyway, this only work in Enterprise edition and above (included Unlimited and Performance edition), so if you are using Professional edition, this is not applicable and hope Salesforce will implement Salesforce Identity for Professional edition.