The present disclosure provides systems and methods that leverage machine learning to implement context determination and/or text extraction in computing device applications. Particular embodiments can include and use a machine-learned text extraction model that has been trained to receive one or more messages containing text and determine one or more portions of extracted text from the one or more messages as well as a corresponding user context assigned to each of the one or more portions of extracted text. In addition, or alternatively, particular embodiments can include and use a machine-learned context determination model that has been trained to receive one or more portions of device data from one or more input sources available at the mobile computing device and determine a current user context indicative of one or more activities in which a user of the mobile computing device is currently engaged.