The way BeNaughty works is very similar to Tinder or Badoo. Users can create their profiles using Facebook or their email, and add all the photos and info they want. You can specify interests, age, relationship status, etc.
Once you've set up your profile you can start looking for interesting people located near you. The main thing is to specify the gender and age range you're interested in. For example, you can choose to only see profiles of other male users between 25 and 45 years of age.
BeNaughty is a very direct hook-up app that mainly seems to work properly. Its only problem is that it does seem to have a few fake profiles... and that it charges you to start talking to another person. In other similar apps you can chat without having to pay.