If you connect to Creep.im via Tor due to security concerns regarding your location or identity, you may want to use Creep.im's own hidden service address — creep7nonbdm4nad2qbmri7z32ajg2l4vcwvzpxnty6wupvc5vfreoad.onion. This is the preferred way to use XMPP over Tor, due to the fact that your traffic will not go through Internet exit nodes which may be ran by some malicious third parties.
This is a guide which will hjelp you how to setup a new account with a popular Conversations mobile client, using Creep.im's own hidden service in the anonymized Tor network. Tor connectivity can be achieved using the Orbot mobile app.
Conversations is a paid app on Google Play store and free on F-Droid marketplace. Orbot is free on both.
Open Orbot. Push "Start" button. Make sure it successfully started and the "onion" icon appeared in the status bar in the top-left corner of a screen.
Once Orbot is up and running, open Conversations. Tap the overflow menu icon in the top-right corner and go to Settings. Once in Settings, scroll down and tap Expert settings.
In Expert settings, locate the Connection section and tick both the Connect via Tor and Extended connection settings options.
At this point you already have a working connection to the Tor network, and your client app is instructed to use it. Now you only need to create a new XMPP account using the onion address to connect to Creep.im anonymously.
To create a new account in Conversations, tap overflow menu button in the top-right corner again and go to Manage accounts screen. Tap Add account button.
Enter your desired account name (XMPP address), new password, creep7nonbdm4nad2qbmri7z32ajg2l4vcwvzpxnty6wupvc5vfreoad.onion in the Hostname field (port: 5222) and tick the Register new account on server checkbox. Press Next.
Now you have instructed Conversations, that although you have a @creep.im address, still the connection should be made through the Tor network, using the provided onion address.
You will be presented with a captcha challenge. After you solve it, you'll get automated Welcome to Creep.im message, which means your account was succesfully created and is now usable.