Notifications are a key feature on current smartphones. Apps gain the attention of the users to inform them about new messages, upcoming appointments or system updates. Previous studies investigated how many notifications users receive and how users interact with those notifications. Related work explored means to manage incoming notifications. In this work, we present the Notification Dashboard to enable users to reflect on their received notifications and to identify unwanted interruptions. We conducted a user study, in which we logged participants' smartphone notifications for one month. Afterwards, we visualized the log files using the dashboard and interviewed the participants about their impressions. The results show that participants underestimated the amount of notifications and were positive about using the dashboard to reflect on their received notifications.