You may already be using Microsoft Teams on a computer to remotely join meetings and collaborate on projects with colleagues. But Teams is also available as a Mobile App (download it from Apple's App Store for an iPhone or iPad, or from Google Play for an Android device). The iOS and Android versions have the same basic functionality, though there are some minor layout differences.
Depending on your needs, preferences and devices, you may find that one device (and orientation) works best for you. Smartphones are portable, but their small screens have limitations. Tablets can be a great companion device to a PC for chat, meetings and more. Below is a side-by-side comparison of two popular Apple devices:
Note: Sizes are diagonal and changing orientation of either device changes how the interface looks/works.