Answer: Can I open whatsapp app from android webview

@Override
        public boolean shouldOverrideUrlLoading(WebView wv, String url) {
            if(url.startsWith("tel:") || url.startsWith("whatsapp:")) {
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setData(Uri.parse(url));
                startActivity(intent);
                return true;
            }
            return false;
        }

Put this code in your mWebView.setWebViewClient(new WebViewClient(). it will be working perfectly for all link like tel:, whatsapp: etc.