You have to enable lock screen in setting.
If you do not want pin lock, you can just enable slider lock.
1. Slide to unlock so smooth and easy.
2. Can set password if want more security.
3. Show time and date on your lock screen.
4. Can choose different beautiful flag images from backgrounds.
In case you forgot your password, you can press home button to unlock.
Brazil Flag Pin Lock Screen
This app has access to :