AFAIK the only way to watch your own content is via RCA connectors:

https://www.flyertalk.com/forum/brit...rtainment.html

This is only a feature on certain classes - e.g. it isn't on WT.

Something like this (for Android) would do it:

https://www.amazon.co.uk/gp/product/...GGDZKX5BZ19PV3

For Apple devices - you'll have to get the old style 30 pin connector AND a lightening adaptor.