You should replace your previous version of MacID for OS X with this new version.
At the start of 2018 I released an update to MacID which fixed numerous bugs with Bluetooth, however Apple made me change the name. So MacID is now called Unlox, and is available as a separate app in the App Store.
People who paid for MacID 1 can get Unlox either for free or at a discount through the Unlox upgrade bundle which you can find on the App Store. Apple decide how much to charge you based on how much you paid for MacID, and when you paid it.
You can find out more about Unlox at unlox.it, and there's lots of information on the FAQs and blog about why Unlox is a separate app on the App Store.
Please try out Unlox if you're running High Sierra, it's a nice update that took me months of work re-writing the whole app to be more reliable after years of workarounds for various Bluetooth bugs.
Thanks for your support over the years!