I there an app on the ipod for jackinchat or something similar to it?

Apple is not going to sponsor something like that. You can however, create a link to this web-site.

Check out the Grindr app for iPhone, iPod touch, iPad, Blackberry OS and Android devices. See wikipedia for further info on this app

Yep, there are several apps you can use to access the chat from an iPod Touch, iPhone, or iPod. You need to find an IRC app, I use one called Colloquy on mine. It runs a few dollars, but it works well.

To configure it:
in the Colloquy app on the iPhone, you would be in the Connections part, hit the + button and select IRC connection.

Fill in Description: Jackinchat
Address: irc.dal.net
Nickname: whatever name you want to use, i.e. pornlover69
Real Name: don't put your actual name unless you want people to see it. can put in there whatever you want
Join Rooms: tap on that and add: #jackinchat (it needs to have the # sign and no spaces)

Then hit Connect and you should be good to go