There is a "Circle" app for iOS. Its features may be limited, especially when it comes to embedding videos.The best alternative option is the webbrowser.
You can save your email/password in the browser (or the keychain on iOS) to make logging in much easier.Browsers have the option to save a shortcut to FloorWorld onto the start page.
This way it appears like an app which is very useful.I experienced loading issues with the Chrome browser on my Android phone. With FireFox everything is working perfectly.