This blogpost is mainly for documentational reasons so I have a document to give people when I give them an account. This will be a chronological list of stuff happening before you got the message and stuff you will have to do. You should be able to guess these categories from context.
-1. I created you an account with some password
0. I sent you your ID and a password
1. depending on your operating system install one or multiple of the following apps:
a) Android: Pix-Art Messanger or Conversations
b) iOS (Apple): ChatSecure
c) Laptop/Desktop: gajim (it's ugly, but it kinda works)
2. You should find some way to add an account to the app: username is the username I sent you, the password is the password I gave you.
a) I don't exactly remember how the screen looks in the beginning and have not device to try. I will add this once I know ;)
b) I only remember you have to clear the port to tell the app to autodiscover (which works fine as far as I know)
c) for Gajim click on the top-left on gajim->accounts->Add Account...->I already have an account I want to use->Jabber ID is your ID, please use your brain to notice the split at the @. Password is the password I gave you. The Authentication is not Anonymous, decide yourself wether to save the password or not to.
3. There should be a subscription request from firstname.lastname@example.org, which is me. If it isn't there,
a) This should be unified and I guess your intuition leads you better than my broken knowledge about android
b) I am sorry not to know this. honestly (ashamed laughter)
c) Accounts (upper left)->Add Contect-> Jabber ID is email@example.com (or later the JID of whoever you want to add to your xmpp-contacts) and if you like to you can give me a nickname only you will see (like "that creepy dude", "bro", "sis who doesn't know they're trans yet" or whatever you like)
4. Profit. OK, there is one last thing to do: make sure our connection is encrypted, but I will be able to guide you on this with XMPP, so I see no big need to explain this here.
If there is a problem with this guide or you want to show me how stuff looks with one of the mobile apps, so I can describe it here better feel free to contact me And a sorry in advance for file transfers currently not working. I am looking for some time to fix this.