How to remove "XXX is an application downloaded from the internet. are you sure you want to open it" at start up?
The app is almost certainly in your Login items.

To check and remove it, do this:


Go to Apple > System Preferences > Users &amp; Groups
Make sure your User Account is selected at top left
Click on the Login Items tab
Look for an item called TunesGoWatch (or something else that could be triggering this) in the list of login items
Now remove this item by clicking on its name (so it's highlighted) and then clicking on the minus - button
Once it's removed, exit System Preferences
Restart your Mac to test to see if the problem still persists