I always thought that making your LED flash when getting a notification needs downloading an app, but it turned out that I was wrong, its an option in general settings under Accessibility, general>accessibility>LED flash alerts ON.
thanks hornet and Q8ping, very useful stuff.
If you have more than one account like me (Kuwait/US) then please read the warning carefully.
“This Device Is Already Associated With an Apple ID.
If you turn on Automatic Downloads with your Apple ID, you cannot auto-download or download past purchases with a different Apple ID for 90 days”