There is a nice methodology available at oasam to begin android pen-testing. These days so many tutorials are available to begin android pen-testing in which I prefer the guide from infosec institute by Srinivas and manifestsecurity by Aditya Agrawal.
A big bundle of tools,frameworks and methodologies are listed in mobilesecuritywiki
UPDATE:
AndroBugs is a framework written by Yu-Cheng Lin for security analysis of android apps. It can check for coding bad practices,ssl enforcement of urls,and much more. We can configure it with MongoDB for massive application analysis.