Adding download tab will give a browser look and while submitting the app to google play, it will get added to the browser list. It affects your app rankings. And moreover downloads are well handled BY Android.
A regular license allows an item to be used in one project for either personal or commercial use by you or on behalf of a client. The item cannot be offered for resale either on its own or as part of a project. Distribution of source files is not permitted.
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