Apps like Doomsday Clock

Here are some great alternatives to Doomsday Clock by Aethervex :
Doomsday Algorithm Trainer
Doomsday Algorithm Trainer
★4.8
TAI Clock and Converter
TAI Clock and Converter
★4.1
New Year Countdown 2025
New Year Countdown 2025
★4.3
Flip Clock-7
Flip Clock-7
★4.0
Decimal Clock
Decimal Clock
★3.9
Smart Clock, Digital Clock LED
Smart Clock, Digital Clock LED
★4.4
Flip Clock: Timer for Study
Flip Clock: Timer for Study
★4.7
AstroClocks
AstroClocks
★3.7
Analog Clock 24-7
Analog Clock 24-7
★3.8
Ancient Clock Widget
Ancient Clock Widget
★4.5
Alarm Clock App
Alarm Clock App
★3.8
World Clock - Global Clock
World Clock - Global Clock
★3.9
Nixie Tube Clock Widget - Pro
Nixie Tube Clock Widget - Pro
★4.1
The Clock: Alarm Clock & Timer
The Clock: Alarm Clock & Timer
★4.3
Digital Clock : Bed/Desk Clock
Digital Clock : Bed/Desk Clock
★4.0
SmartClock - LED Digital Clock
SmartClock - LED Digital Clock
★4.5