Here are some of the characteristics behavior designers use to make you addicted:
The People Who Pay For Your Free Apps
Megan E. Holstein

I really like the points made here and simply broken down so that these tactics are easy to understand. I think sometimes these design tactics are blown out of proportion and we think characteristics like these can only be understood by computer scientists or programmers. In reality, these tactics are more engineered towards our psychological behaviors and understanding how our brain functions we understand our behaviors better. I think it is important for us to educate ourselves on these strategies to avoid us getting to that “addiction” point where the apps begin to consume our lives- something that can tend to be very unhealthy.