I've used both, Norton's antivirus security has a feature I liked that give you information on activities apps was doing on your device and where it was sending information to on a map and it was a paid version at $16. 99 for a yearly subscription. Lookout antivirus was more expensive with a $3. 49 monthly subscription, It also flagged apps with malicious activities. In hindsight neither was really needed unless you just like to know what particular apps are doing in your device. Some mobile carriers give you Lookout Antivirus for free when others charge you after a 30 day trial is over. But at the end of the day it all came down to personal preference if you wanted either or not. But if you just really want some on your device you can play around with Comodo antivirus. It's lite weight and it will notify you if it detects anything malicious and it scans all your apps when you download them, and it also comes with an app lock you can set a pass code with.