A few points to note from what I've read:
- iTrack Solo will come with a Lightning connector for your iOS device. Previous versions had the 30 pin cable included, however these are legacy units and you should ensure you're purchasing the Lightning connector version. They also come with a standard USB cable for connection to computer.
- Scarlett Solo 3rd Gen has better audio specs than it's previous 2nd Gen iteration, and the iTrack Solo. As such, if iOS recording is not required (ie you're just using a computer), I'd get the Scarlett Solo 3rd Gen. Please note, that while not officially supported at this time, Scarlett devices will work with iOS devices as they are 'class compliant', however the bus-powered Scarlett's will require the Apple camera connection kit in order to power them at the same time. Scarlett's have a USB-C connection on them, but come with a cable that connects to a standard USB-A port. They will of course work with a USB-C to USB-C cable if that's the connection on the computer.
Hope that helps, please let me know if you have any further questions
Si // Focusrite Media Relations