MKV is not a popular video format. Currently we fully support image snapshots and MP4 videos. We also support AVI video format in our mobile apps for iOS, Android and Windows Phone.
Our Android version CameraFTP Viewer app supports .MKV video format. On PC and Mac, you can install VLC player to play MKV files. (You will need to download the MKV files first). If you need to download multiple files, you can use any FTP client, such as FileZilla. (Our FTP server is: ftp.cameraftp.com)