Detect in-app browser (WebView) with PHP / Javascript

I'm not sure about Android, but when you're using the iOS SDK's UIWebView, it sends the name and version of your app as part of the user agent (YourApp/1.0).

You can then use PHP to check if your in-app webview is being used or not:

if (strpos($_SERVER['HTTP_USER_AGENT'], 'YourApp/') !== false)

I think Android does something similar as well.

Solution code:

$isWebView = false;
if((strpos($_SERVER['HTTP_USER_AGENT'], 'Mobile/') !== false) && (strpos($_SERVER['HTTP_USER_AGENT'], 'Safari/') == false)) :
    $isWebView = true;
elseif(isset($_SERVER['HTTP_X_REQUESTED_WITH'])) :
    $isWebView = true;
endif;

if(!$isWebView) : 
    // Android or iOS Webview
else :
    // Normal Browser
endif;