How to avoid 'Move to Applications folder' prompt?
Although this is hard to check, it seems like Gatekeeper was being overly-protective, but has since been adjusted.

When using macOS Sierra (10.12) or later, if an app is in /Applications/ but prompts to be moved to /Applications/ when run, then chances are very high that the app has recognized that it has been subjected to Gatekeeper’s “app translocation”. If you’re interested in the details you can find them online, but the practical effect is that if you went into Terminal (or iTerm) and ran

ps auxwww | fgrep -i YourAppHere 

You would see a path that is not /Applications/YourAppHere.app but more like /private/var/folders/[something-random-looking]/AppTranslocation/YourAppHere.app.

The preferred way of moving apps around (according to Apple) is with the Finder. If you drag an app from the ~/Downloads/ folder to /Applications then it will not be 'translocated'.

If you insist on not doing things Apple’s preferred way, your only option is to remove the quarantine flag from the app. This will remove all of Gatekeeper’s protections, so use at your own risk. You can remove the quarantine flag using this command:

find "/Applications/iTerm.app" -exec xattr -r -d com.apple.quarantine {} \;


Replace "/Applications/iTerm.app" with the appropriate app name as needed, obviously.

You will need to re-launch the app for the app translocation to go away.