From http://stackoverflow.com/questions/14555040/allow-all-market-links-from-inside-a-webview-to-open-google-play-store

Market.java

webView.setWebViewClient(new WebViewClient() { 
    @Override 
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        if (Uri.parse(url).getScheme().equals("market")) {
            try { 
                Intent intent = new Intent(Intent.ACTION_VIEW);
                intent.setData(Uri.parse(url));
                Activity host = (Activity) view.getContext();
                host.startActivity(intent);
                return true; 
            } catch (ActivityNotFoundException e) {
                // Google Play app is not installed, you may want to open the app store link 
                Uri uri = Uri.parse(url);
                view.loadUrl("http://play.google.com/store/apps/" + uri.getHost() + "?" + uri.getQuery());
                return false; 
            } 
 
        } 
        return false; 
    } 
}); 

view.loadUrl("http://play.google.com/store/apps/"