I have to apologize for misleading here. 'Store' plugin was originally developed for Oxwall.org needs and it has a lot of specific functionality in it. That is why we're not planning to release it in future for public use. The reason is impossibility of its development.
We are planning to constantly improve and develop the existing Store making it more user-friendly and available for all users. Available plugins will be added to Oxwall Admin Panel, by doing this we are planning to attract as many software users to Store items as possible.