macOS blocks apps from unknown developers by default. Here's how to open RepairIQ — it only takes 10 seconds and you only need to do it once.
Double-click the downloaded RepairIQ-macOS.dmg file. Drag RepairIQ to your Applications folder.
Go to Applications, find RepairIQ, and right-click it (or Control+click). Do NOT double-click.
A menu appears. Click "Open" at the top of that menu.
macOS will show a warning. Click "Open" again. That's it — RepairIQ will launch and never ask again.
xattr -cr /Applications/RepairIQ.app
Then double-click RepairIQ normally.