You will first need to install TestFlight on your Mac to be able to download and install the beta versions of the apps. In the TestFlight process you are technically enrolling your Apple ID, not a specific device. Details on TestFlight and how to install it can be found here: https://testflight.apple.com
Here is the direct link to download testFlight for Mac: https://itunes.apple.com/us/app/testflight/id899247664?mt=8
After TestFlight is installed on your Mac you can click on each of these links to install the Mac versions of the LIT SUITE apps:
TrialPad: https://testflight.apple.com/join/DDE7ixbf
TranscriptPad: https://testflight.apple.com/join/Mf0ncPm3
DocReviewPad: https://testflight.apple.com/join/b8WZS8BA