AngelTalk is designed to promote language development and grow communication skills of children with Angelman syndrome (AS). Because most children with AS cannot speak and have a short attention span, the only possible way to understand their needs and validate functions for the app was to observe them. The developers of the app decided to use flash cards as a non-verbal communication tool. Each flash card contains a photo of a real-life object. Hence, the children are not distracted as they can only see one flash card at time.