We live in an era where the boundaries in mobile vs. non mobile is getting thinner day by day. Is an iPad considered a mobile device? If you plug a keyboard to your iPad, is it a laptop or a mobile? Not so easy.
At Air360, we took an approach where you can segment by operating system (iOS, MacOS, Windows, etc.) but leave it up to our users to device what should be considered mobile or not depending on the use case.
In Users segment, you can do this very easily by enabling the filter on User platform as shown below.
Which will then ask you to select which platform the user should match.
It could be only one or a combination of multiple ones. For example, below we created a filter that will only keep Android and iOS users. Sounds like a good way to filter smartphone & tablet users. But do keep in mind that Android could be also a PixelBook for instance.