SECURE instant messages

[wonky]

Here are some secure instant message apps I've seen listed on the EFF website:
https://www.eff.org/secure-messaging-scorecard

I am looking for the best secure Instant Message application to communicate with my nieces and nephews. It has to send and receive encrypted messages and files.

What I would like
* reliability & ease-of-use (will be used with nieces and nephews, the oldest of which are 12)
* the ability to be able to keep all messages saved (& exported to text file on demand)
* an app that never updates without my explicit permission

Bonus points:
* if it doesn't have the in-built capability to connect to any existing spyware network (Facebook, MSN, etc.)

Your thoughts?
Just thought I'd ask here before I try several of them to see what suits me.

 

[wonky]

Nobody using secure messaging?

 

[Hadron]

Well I can tell you that "never updates without explicit permission" is easy: turn off automatic updates. You can't stop the Play Store or Google Play Services updating themselves that way, but other apps, certainly.

Otherwise nope, I don't use them.