Update May 14th 2019: See https://shuttersnitch.com/eyefikey for a guide on how to extract the card key(s) from a Keenai Desktop installation and adding them to ShutterSnitch.
*** Ignore these next paragraphs. They were written before we figured out how to obtain the keys ***
Follow this link for the guide on how to obtain and add the card key to ShutterSnitch.
To get your Eyefi Mobi Pro card transferring to ShutterSnitch, it needs to be added to your Eye-Fi account.
First, if you haven't already, get your card set up on your computer by installing the Eyefi Mobi Desktop application.
Once you have things working and photos transferring to your computer, close the Mobi application completely and install the Eye-Fi Center Desktop Software.
When it's installed, insert your card into your computer and the Eye-Fi Center application should detect it. Sign up or log into your Eye-Fi account.
Once you're signed up / logged in, the card should be added to your account. If you have more than one card, you can right-click the card in the left pane and choose to rename it. That'll make it easier to distinguish between them.
Now that it's added, you can open ShutterSnitch on your iOS device, go to the collection overview, tap the Options button and pick "Setup Guide". Then pick the "Eye-Fi card" option (*not* the "Eye-fi mobi card" option). Then sign into your account and your Mobi Pro card should be in the list. Turn on the switch to the right of it and you'll be ready to receive files when you're inside a collection.
You only needed the Eye-Fi Center to add the card / create an account, so you can uninstall that and just use the Mobi application on your computer from now on.