1. 1.   Introduce

You can develop a app to get report about user activities(Admin/Docs/Login).

It have been replaced by the Admin SDK’s Reports API

https://developers.google.com/admin-sdk/

1. 2.   official Description

The Reports API lets you customize usage reports across your whole account, for example, the number of logins in the past 30 days. And the API's activity reports let you understand user activities in specific Google Apps services such as the Admin console and Google Docs and Drive.

(https://developers.google.com/admin-sdk/reports/ )

1. 3.   Set up the basics

• Get a Google Apps account and create an administrator. You can create user accounts and delegate administrator privileges from the Google Apps Admin console or using the Directory API.
• The Reports API applies to Google Apps for Business, Education, and Government accounts.
• Be familiar with your Google Apps Admin console found at admin.google.com. For more information about the Admin console, see Use your Admin console.
• The Reports administrator privilege must be enabled when using the API. A super administrator has this privilege. For delegated administrators, create a custom administrator role.

(https://developers.google.com/admin-sdk/reports/v1/guides/prerequisites )

Explain:

admin.google.com: when you create a business account, you can login in successfully.

1. 4.   Reference

• sign up account

http://www.google.de/intx/zh-CN/enterprise/apps/business/

Follow the step , go to next.

• Video: New Admin console overview

https://support.google.com/a/answer/3166259?hl=en

• I have a test account, if you have interest, try it.