Android 5.0 Lollipop introduced a new Smart Lock feature. Smart Lock allows you to declare specific situations where you want your phone to be unlocked.
I use this feature and find myself only having to enter my PIN 1-2 times per day.
Here's how to do it.
I use "Trusted devices," "Trusted places" and "On-body detection."
While "Trusted devices" and "Trusted places" are pretty obvious, "On-body detection" is more subtle.
"On-body detection" keeps the phone unlocked while it is moving such as in your pocket. When the device becomes still for a few seconds it locks and requires the PIN to access. An example is when you set the phone on a table for a few seconds it locks. Nice.
Overnight, specifically after 4 hours idle, the phone locks regardless of trusted situations.
As always there are 2 sides to this story. Here's the other.
Remember what the president of our company said "iPhone users just don't understand what they're missing."