BigBlueButton app for tablets. It allows you to share your screen in a BigBlueButton room, and also provides improved background audio.
PS: This runs on mobile too, but it's mainly targeted for tablets, as it requires good CPU due to usage of a webview for rendering BigBlueButton.
More details in https://github.com/bigbluebutton/bigbluebutton-tablet-sdk
- iOS version available in App Store