Web
Embedding the iframe in a regular web page is the most common scenario. You drop an ` tag into your markup and listen for messages on window`.
iOS
On iOS the iframe communicates with the host application through the webkit bridge. Configure a WKWebView with a script-message handler named bridge and decode the JSON string the iframe posts.
Android
On Android the iframe communicates with the host application through an injected JavaScript object called legitHealthJsObject. Use WebViewCompat.postWebMessage to wire it up.