It is a real pity that we can't set up previous version directly in liferay. Actually liferay should automatically select the best version to work with depending the liferay'version.
First purchase the 2.0 app. Then click on Purchased to see your apps. Click on Open Social. Then click on Past Versions to get 1.0 version.
I would like to download 1.0.0 version. Is it possible???