I can tell you the best Applock. No 1 Android Applock to protect app! Lock up your Facebook, WhatsApp, Clash of Clans, Messenger, Gallery and other important apps which may leak your privacy with LEO Privacy. And it can also protect your privacy by hiding images and videos.
Kaspersky - I think so. Through it is expensive but you can't negative its great features and the support team from its company. I have used it for 4 years and I will continue to use it.