Whatsapp bridge is now part of the matrix so you can get it if you update, but it does not work correctly with dendrite (next gen matrix written in go lang which I use).
You can start the chat with the bit but it will not respond 
@whatsappbot:matrix.[your domain]
Their issue to track is here: bot issues with latest dendrite · Issue #2902 · matrix-org/dendrite · GitHub
With the latest update there is a workaround for whatsappbot, create a public room invite it (two times :)) then make the room private.
it joins and leaves each time, had to do this i think 4 times
:correction:
Is it a public room?
Their issue is still open, I am trying to help them getting it fixed, progress unfortunately is slow.
Just pushed an update it should be a bit better but still multiple attempts, repeat this not more than 10 times
With version number the whatsappbot is working ?
Pierre
It is working but you need to invite it fee times still untill it stays and responds to help nessage once invited will not leave.
Listening to the verge on beeper, since they have a self host option, i do think it would be a good idea to add it
Ok beeper is actually built on top of Matrix server called Synapse which is written in ruby as I remember and is usually slow and resource hungry. That is why I decided to take their lightweight go implementation called dendrite.
So I would still continue adding bridges to dendrite because you would have to do the same thing for beeper anyway. I am not even sure why beeper exists if they modify the same source code (Synapse).
By the way whatsapp bridge works really good (as soon as you invite the bot after few attempts).
If you want more bridges let me know which one do you want more?
Telegram, Signal, Discord, Slack
I do have a question in terms of cache and storage though, i.e. will these bridges keep the content on the hosted service, i.e. whatsapp images stay on whatsapp or are those images also downloaded to the matrix?
Probably depends on network, but what I see on WhatsApp everything I do through matrix stays on both.
Just try, it is already there.
AHh i see, hmm it is tempting to figure out how to keep it on each other services. I saw today that texts.com was bought by Wordpress owner and that seems to go the route of keeping on the hosted services… which is interesting and will be interesting it if it made fully open source
OK before adding telegram I will need to add SlidingSync feature as ElementX needs it and I really want to see how this next gen client looks like. Should not take too much time.
Sliding Sync is out, so you can try ElementX now.
Will look at telegram bridge now.
Telegram (part of the Matrix app) is out please try it out.
You will need to talk to @telegrambot:matrix.[your domain]
Signal and slack is there!
Discord is in progress.
