Plays karaoke songs. Comes with offline syncing capabilities and dual screen support.
— How much does this service cost and once I have made a playlist of songs can I then transfer to my iPod to use when I'm singing elsewhere?
The software is available for downloading on multiple platforms including iOS. According to their offers page, the software is available for downloading but you actually need to buy a subscription... in order to use it on the available platforms.
Here is page with the subscription info: https://www.karafun.com/subscribe.html
Note: A valid payment needs to be completed before you can actually buy the subscription. Read more