This article provides information about how to search App Web content using REST API.
Implementation
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Additional Data You can use developer tool to obtain additional result elements of Primary or Secondary Result from JSON and use it to display on the page. Here results[3] and results[6] have been used for display purpose. Conclusion This function can be used to get search result from App Web. Examine the returned JSON data to get more results elements. Styling can be done to display the result in any format.
SharePoint 2010 Administration & Development