DR Viewer A by DENSO TEN Limited is an Android app designed to playback recorded videos from the built-in navigation "Record Navi" drive recorder. Using Wi-Fi tethering, users can connect to the car navigation system and transfer recorded data to their smartphone. The transferred data can then be played back using this app. Additionally, users can save their favorite videos to their smartphone and play and edit them outside the app. It is important to note that transfer is only possible when connected to the car navigation system using Wi-Fi tethering and that car navigation operations are required for transfer.

To link the app with the car navigation system, users need a smartphone that can use tethering and a compatible car navigation system. It is also important to keep in mind that operating the driver's smartphone while driving is extremely dangerous and can cause accidents. Therefore, it is recommended to use the app only when the car is stopped or by a passenger. Finally, an internet connection is required to use the app, and communication occurs during playback of recorded data, so it is recommended to subscribe to the packet flat-rate plan.

Overall, DR Viewer A is a useful app for those who want to playback recorded drive videos on their smartphones.