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

[Dagambina]

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.