What's new in AtomicClock: NTP Clock 2.1.21

• Redesigned the color picker for app and widget colors, with presets, a color wheel, and brightness control
• Pro: widget backgrounds can now be customized with color and opacity, and default widget colors follow your Android theme better
• Settings now use clearer icons to make customization options easier to scan
• Custom NTP servers now support host:port entries and better validation before saving

About AtomicClock: NTP Clock 2.1.21

Need the exact time to set a watch, set a wall clock, compare UTC, or catch a moment where seconds matter? AtomicClock shows precise reference time from NTP time servers in a clean analog and digital clock display.

Use AtomicClock as an atomic clock, NTP clock, UTC clock, reference clock, or everyday precision clock when accurate seconds are important.

Core features:
• precise current time from NTP servers
• local time and UTC time
• analog clock and digital clock views
• customizable home screen clock widget with time and date
• predefined time servers and custom time server selection
• 12-hour and 24-hour modes
• customizable time format
• multiple clock faces and clock hands
• smooth fluid second hand
• acoustic ticking sounds
• Greenwich Time Signal
• technical NTP details such as round-trip time and stratum
• screen tap actions to hide info, freeze the screen, or mute ticking
• picture-in-picture mode

AtomicClock is useful for manually setting watches, wall clocks, cameras, and other devices, checking exact time before an event, comparing local time with UTC, or keeping a clear seconds clock on screen while you work.

For technical users, AtomicClock can show NTP server information so you can see more than just the clock face. Accuracy depends on the selected time server, network conditions, and device behavior.

AtomicClock is free to use. Some advanced features require AtomicClock Pro, available as a one-time purchase with no subscription.

AtomicClock: NTP Clock 2.1.21 screenshots (6)

Download AtomicClock: NTP Clock 2.1.21

This release comes in several variants (we currently have 2). Consult our handy FAQ to see which download is right for you.

Variant
Arch
Version
DPI
2.1.21 BUNDLE 28 S
140
June 30, 2026
arm64-v8a + x86 + x86_64
Android 8.0+
480dpi
2.1.21 BUNDLE 23 S
140
June 30, 2026
arm64-v8a
Android 10+
480-640dpi
All Releases
AtomicClock: NTP Clock 2.1.21

Version:2.1.21

Uploaded:June 30, 2026 at 7:44PM UTC

File size:4.45 MB

Downloads:2

AtomicClock: NTP Clock 2.1.20

Version:2.1.20

Uploaded:June 16, 2026 at 9:23AM UTC

File size:4.49 MB

Downloads:26

AtomicClock: NTP Clock 2.1.19

Version:2.1.19

Uploaded:June 15, 2026 at 1:32PM UTC

File size:7.88 MB

Downloads:12

AtomicClock: NTP Clock 2.1.18

Version:2.1.18

Uploaded:April 16, 2026 at 11:59PM UTC

File size:7.45 MB

Downloads:60

AtomicClock: NTP Clock 2.1.17

Version:2.1.17

Uploaded:April 15, 2026 at 5:30PM UTC

File size:6.98 MB

Downloads:39

AtomicClock: NTP Clock 2.1.16
December 21, 2025

Version:2.1.16

Uploaded:December 21, 2025 at 5:51AM UTC

File size:4.67 MB

Downloads:52

AtomicClock: NTP Clock 2.1.15

Version:2.1.15

Uploaded:October 17, 2025 at 7:48AM UTC

File size:4.55 MB

Downloads:40

AtomicClock: NTP Clock 2.1.14

Version:2.1.14

Uploaded:August 8, 2025 at 9:17AM UTC

File size:7.16 MB

Downloads:60

AtomicClock: NTP Clock 2.1.13

Version:2.1.13

Uploaded:August 1, 2025 at 6:06PM UTC

File size:7.14 MB

Downloads:33

AtomicClock: NTP Clock 2.1.12

Version:2.1.12

Uploaded:July 6, 2025 at 7:43PM UTC

File size:6.95 MB

Downloads:30

Comments