Use the Photos App to view downloaded videos. If it’s a recent video, start with the Recents folder. Video and Photos can be located under the ./internal storage/DCIM folder.
Your phone should have a default "Gallery" application. Open the Application. Within Gallery, videos can be located in an Album titled "Drive_Smarter". The location of the folder is ./internal storage/DriveSmarter/Drive_Smarter. Within Gallery, Drive Smarter Photos can be located under Images. The location of the folder is ./internal storage/DriveSmarter/Images.