Here is method how to connect DVR/NVR on phone app xmeye.

https://hview.kf5.com/hc/kb/article/1032179/?from=draft

After app xmeye connects system successfully, you can record or take snapshot to your phone's storage.

When it is blue, means it is recording and tap it again to stop recording.

Click on the local Record and here you can see video.  

Click on Menu and Download.You can download video to your phone's storage. But the size of file may be huge.