A blog post on the blog 'Ninetwozero' written and maintained by Karl Lindmark, the developer of a Battlelog application for your phone (which was later removed from the Google Play Store), revealed that after doing some research and strolling on the Battlelog Forums he came to the conclusion that people would appreciate it if they could communicate with their contacts and friends on Battlelog via their handheld device. So, for the second time he got back to work and delivered a new unofficial Chat App for Battlelog! The App is dubbed as 'Battle Chat' and is only that, basically. It enables you to "Just log-in via the form and you’ll be able to chat with your friends within seconds!". logging with your Origin credentials is 100% safe as they will only pass onto Battlelog once per login. It won't store your password anywhere, not even on your device, and whenever your session time ends you'll be forced to re-login once you open the app again next time.
Not only that, but mister Lindmark also included a link in the post to the source code of the app just so other people can learn from it or toy or experiment around with it.
A link to his blog post: http://ninetwozero.com/2013/02/15/say-hello-to-battle-chat/
The link to the Google Play Store Battle Chat App: https://play.google.com/store/apps/details?id=com.ninetwozero.battlechat