The most recent update of Skull Pin Screen Lock was released on Sep 20, 2019 and the app has been set up by over 1M users. Adverts are a part of this application. A lot of users set up the app on their Samsung and Asus devices.
A free .apk installation package of Skull Pin Screen Lock 4.3 is available from Droid Informer and you can read users' reviews on this site. Prepare 7 MB of free space on your device for this app setup package and keep in mind that it works fine on Android 4.0 and above.
Users write reviews stating that you can notice such a disadvantage of the app as many ads.