This beta isn’t notarized yet. MacOS Gatekeeper will warn you. That’s expected, not malware. You drag Noggin to Applications, then tell MacOS Open Anyway.
FinderFileEditView
Noggin
“Noggin.app” Not Opened
Apple could not verify “Noggin” is free of malware that may harm your Mac or compromise your privacy.
System Settings
Wi-FiGeneralPrivacy & SecurityTouch ID
Privacy & Security
Security
Noggin was blocked from use
because it is not from an identified developer.
Open “Noggin”?
Apple could not verify “Noggin” is free of malware that may harm your Mac or compromise your privacy.
Open the disk image. Drag Noggin into Applications.
The actual clicks
Open Noggin.dmg. Drag Noggin into Applications. Eject the disk image.
Open Noggin from Applications. MacOS will say it can’t be opened. Click Done, not Move to Trash.
Open System Settings → Privacy & Security. Scroll to the message that Noggin was blocked.
Click Open Anyway. Confirm Open Anyway if it asks again. Touch ID or your password may show up.
Faster path: Control-click Noggin in Applications → Open → Open. Same Gatekeeper exception, fewer windows.
After that, Noggin lives in the camera notch: the menu bar, not the Dock. If MacOS still refuses, check Privacy & Security again. The warning is because this beta isn’t notarized, not because the file is damaged.