I like to add in my video clips a watermark. I use a android tablet. Should  knows a useful, all to do the job with *.mp4?
Thanks

To add a watermark to your video you will most likely need to use some type of video editing software. Not sure if this is something you can do from your tablet. Try Adobe Premier, or Final Cut.

It is definitely not doable from the tablet, you need a regular computer.

As Goes for format, You can freely pick mov or mp4. Just like guyes before said, to add watermark you need video editing software (even freeware can do this job). But it is not possible from tablet in dji app. Or....You can put little sticker on Phantom lens! ;)

Use some Watermark Expert Software like EasePaint Watermark Expert if you are not familiar with PS or other professional photo editing software.
It can help you to add Image or Text Watermark to both videos and photos easily. In case you want to remove the watermark in the future, the software offers a watermark removal tool to help you to remove the watermark easily as well. Try it out of the software above! I hope it can help you to add a watermark to your video without any problem.

Almost any editing app would have the option for watermark.

I think using  PC video editing software like TunesKit AceMovi is much more easier.

Premiere is good but way to expensive for the sake of just one watermark.