Scarlett Itrack vs Scarlett Solo -HELP FAST!

I know practically nothing compared to anybody else on these forums so please explain so I can understand. I want to know the difference between the Scarlett Itrack and Scarlett Solo. Just tell me the major differences because I need to know quick. I found someone selling the Scarlett Itrack for $30 and I don't want someone else to buy it if it turns out it does everything the solo does. I just want to use phantom power for my headphones and record vocals using my at2020 I just got. Does the itrack do everything the solo does? I thought the itrack might have some restrictions since it can be used on mobile devices like iPads. Thanks for any quick reply!