Fire Boltt INVINCIBLE PLUS - System Settings and Customization; Display Settings

Setting - You can set Display,Time,Vibration
Strength,Brightness,View Mode,Language,DND,
Power Save,Lock Screen,USB Mode,About and
System Menu.
Screen display: Click to enter the screen
display settings.
Change the Clock Style: Click to enter, slide left
and right to view the dial, click the dial setting as
the main interface.