You can use either. The application works on your phone, tablet, or computer.
Phone is the easier path for ID
If you can, use your phone for the identity verification step. You'll need to take a photo of your ID, and your phone's camera handles this in one go — no need to take a photo on one device and upload it from another.
Some properties also ask for a verification selfie. Phones make this easier too.
Either works for income verification
Bank and payroll connections work the same on both. Document upload works on either, though uploading PDFs from a computer is sometimes easier than uploading from a phone.
Tips
If you start on one device and switch to another, your progress is saved — pick up where you left off
Use a recent version of your browser. Older browsers may have issues with the secure connections used for bank or payroll verification.