AppUsage is a user study to research smartphone usage behavior. How the study works and what you should keep in mind is described below.After downloading the app, among other things, you will be asked to anonymously fill out a questionnaire about your smartphone usage. The app then starts to track which apps you use on your smartphone at which time, but not what you do in each app. All the data we collect is strictly anonymous; no personal data is collected.This data will subsequently be analyzed as part of Arvid Eichners research at Goethe University Frankfurt. The data analysis is only carried out in aggregated form and serves to expand the understanding of various behavioral patterns in the use of smartphones. The data cannot be used to draw conclusions about individual persons.