As of version 1.3 this plugin combines Stefan Reuter’s Open Archive plugin to provide XEP-0136 automated archiving and message retrieval for one-to-one and MUC chat. Support for preferences and manual archiving will follow later.
So, you can use XEP-0136: Message Archiving in your android app to retrieve saved history.
I don’t know how to use XEP-0136 to retrieve the messages. But if you just want to see old messages as described in given example. Then you can use Spark client, It has chat conversation option. It will visible only with those user whom you ever did chat. You can see one month old/1 year old/Show all on the page.