I have two questions here. (1)Can we develop apps for SharePoint Foundation 2013 edition? (2)Can we purchase and download apps for SharePoint Foundation 2013 edition from SharePoint Store?
Yes You can develop and purchase or download apps for SharePoint Foundation 2013.
There is a service application named as App Management Service which lets you install apps from the Internal Catalog or the Public SharePoint Store.
Here's the very detailed list of features for SharePoint Foundation 2013 and SharePoint Server 2013.
Since yesterday the App support is also officially documented on Technet. See yourself
Until yesterday all App relevant features were stated as "No".
I created a ticket about it some time ago, because a lot of other articles about Apps on MSDN were saying that App development is working in SharePoint foundation.
BUT there are limitations though, because User Profile Service Application is not available. So a generic "Yes, apps work in foundation" is still not the full truth.
My reputation is still to low so I can't add a comment directly to the post of Muhammed. But your answer is in contrary to the link you provided. On that site it is a "No" for the App Management Service - just saying