Fiona26 is correct.
Good Lock only appears to be in the Galaxy Store ("Store", white bag on red surround icon in app list). It isn't in Google Play store.
Good Lock has a pinkish background with what look like 4 puzzle pieces, the top two are locked to each other as are the bottom two.
When you have Good Lock open you have to find and install QuickStar and you open it from within Good Lock (once installed).
I'm disappointed with QuickStar because after you turn on Show Seconds, the seconds do not display at the top of the screen. You have to open/drag down the status bar to see the seconds. I wanted the clock in the upper left to show seconds, like I had with my Moto phone.