This is 5 star application. It's free. No add. It doesn't bug you with rate me. Infact I was looking for how to rate the app myself because I want to show it meet my demand. If you care about security and privacy this is your last bus stop. Unlimited functions yet its unlike other security app that give you 70% to 80% free but 30% or 20% buy that is not free. Sophos is not that it support military grade encryption. 100% free and strong security app. It is not power intensive, it is user friendly. They kept it like a secret treasure but now am telling you it is every thing you desire to secure you Android phone.