Skype for Android did never work very well but recently I discovered a really annoying bug: After logging out of Skype, I closed the App in the Appmanager and still receive push messages sent to my account. Most recent version from 18th of March 2014. Bugs known since summer ’13 are still not fixed.
How does Skype communicate, how does the protocol work? A very nice paper about the communication of Skype, use cases for abusing the network as a botnet, worms, techniques. Everything you need to code your own client (or bot), details about the protocol, a working Python library, … Paper by the Sans Institute. http://www.sans.org/reading-room/whitepapers/covert/skype-data-exfiltration-34560 (PDF)