You can choose to monitor your glucose levels with either the app, the reader, or both⁵. You can use the FreeStyle LibreLink app and the FreeStyle Libre reader with the same sensor, as long as you start the sensor with the reader first.  Remember that the FreeStyle LibreLink app and FreeStyle Libre readers do not share data with each other. For example, if you switch between your reader and the app, you may see gaps in your glucose data, which will affect the reports available through the reader, the FreeStyle LibreLink app, and LibreView. It is important to continue scanning your sensor with either the app or the reader at least once every eight hours so you and your healthcare professional can get a complete picture of your glucose trends and patterns.