The User Agent field will show what browser and operating system was used to make the visit.

You can find this field in an offline report which you can download as a CSV file from the reporting area.

Unfortunately, user agent information is never as simple as ‘Google Chrome’ or ‘iPhone 5’, they can look pretty daunting if you’ve never seen one before. There are plenty of useful websites you can use to help interpret the user agent values should you need to do so.