Android App using Webview/javascript. what can be security concern?

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http://stackoverflow.com – I am creating an android web app using Webview and Java script making addJavascriptInterface(true). My App will content data(html) that will be loaded from an external site. I worried about the cross-site-scripting XSS/security of my app as I am enabling addJavascriptInterface(true). what are the thing I should be taking care so that any malicious code should not run on my app. (HowTos)