Lenovo A2107A - Manual (Page 6)

Screen Lock Pattern Setting
You can set the screen lock pattern by tapping Pattern in Screen lock in
Security under Settings. After this function has been enabled, you will
be required to trace a personalized unlock pattern to unlock the screen before
you can use your IdeaTab.
1-6 Navigation Tips
Back : Return to the previous screen.
Home : Return to the Home screen.
Recent Apps : Display recently used apps.
Advanced Menu : Display shortcuts such as Preferences, Manage
apps, System settings, Add more capacity and One touch clear.
App Menu
: Display all available apps.