In addition to learning Apps as a teacher, a few years ago, Google developed a Google for Education Academy where you can go online and take free lessons on some often used Google Apps like Gmail, Docs and Drive, and Search to name a few. The basic test is free and can be taken once you log into your Google account. You get a certificate emailed to you once you pass it.
Level 2 is a little more in-depth and the lessons are free but the exams are $15 a piece. You have to take a minimum of 5 exams so that totals $75. Once you pass the first test, you must complete the final test within 90 days. Pass all five and you have become a Certified Google Educator!!! Many schools will allow you to use your teacher development stipend for this certification.
Certification Details Here
And more free certification tests from Google Web Academy:
Google provides two other exams as far as online assessment goes. And for free? why not!
Here is the link: