You'll need to enable Accessibility support in System Preferences → Security & Privacy → Privacy → Accessibility
Frequently Asked Questions
Q: I'm getting a '“Mission Control Plus” can’t be opened because Apple cannot check it for malicious software' message when trying to open the app.
A: Either Right-Click the app and click Open, or go to System Preferences → Security & Privacy and check "Allow apps downloaded from: App Store and identified developers".
Q: What is included in one Mission Control Plus license purchase?
A: Each Mission Control Plus purchase includes one lifetime license that you can activate on a single computer. Mission Control Plus is sold at a very fair price for you to enjoy, and purchasing it supports the development behind it.