TrueOffset vs CUE! Time Signal Sync
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
TrueOffset
This app precisely measures your device's clock accuracy against global time servers. It offers multiple clock faces, time scales, and audible time signals, including radio time codes. Analyze time source quality with detailed charts and compare IPv4/IPv6 responses.
- NTP server comparison
- Multiple clock faces (analog, digital, NTP offset)
- UTC & TAI time scales
- Audible time signals and radio time codes
- Dual-stack IPv4/IPv6 comparison
- Flexible time source selection
- Quality analytics charts
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TrueOffset measures how far your iPhone or iPad's clock is from the world's time servers, and which way. Compare Network Time Protocol (NTP) servers with one another, see how far apart they are, and set any of them as your reference. FIVE CLOCK FACES - 12-Hour Classic — Traditional analog display - 24-Hour Scientific — Full day on one dial - NTP Offset — Dual second hands show device vs. true time - Digital — Large display with millisecond precision - Time Code — A radio time code spelled out second by second UTC & TAI TIME SCALES Show Coordinated Universal Time (UTC) and International Atomic Time (TAI), 37 seconds ahead of it, beside your local time, with deadbeat second hands that step on each second. TIME SIGNALS Hear the true second. Optional pips are timed against your NTP reference, so the start of each one marks the real second, not your device's idea of it. Choose from the classic broadcast signals, synthesized to their published pitch and timing: Six Pips (Greenwich Time Signal), WWV, WWVH, CHU, Jihō, Moscow Six Pips, and Australia's VNG. Sound them on the hour, every 15 minutes, or every minute. Bluetooth or AirPlay speaker running late? Measure its delay with the microphone and TrueOffset compensates. RADIO TIME CODES A clock sold as "atomic" is a radio listening to a distant station that spells out the time one second at a time. TrueOffset plays the codes of WWVB, DCF77, MSF, JJY (40 and 60 kHz), and BPC and shows each second being decoded as it is sent. Try setting a radio-controlled watch with it (beta), or switch on the DCF77 weather seconds to hear how Germany's station once sent a forecast. TRUEOFFSET MASTER CLOCK Our tribute to the U.S. Naval Observatory's telephone time service. A tick sounds every second while a voice announces your local time and then Universal Time, each ahead of a beep that lands on the true second. Prefer it quiet? Switch the voice off and keep the ticks. TrueOffset is not affiliated with the U.S. Naval Observatory. DUAL-STACK COMPARISON Ask one server over IPv4 and IPv6 side by side, to catch two different machines behind one name or a network that answers for both. FLEXIBLE TIME SOURCES Compare against Apple, Google, Cloudflare, NIST, US Naval Observatory, global NTP pools, or add your own servers. The default reference, ntp.trueoffset.app, is a Safran SecureSync 1200 with its own rubidium atomic clock. Set any source as your reference. QUALITY ANALYTICS Eight chart pages show the character of your time sources: - Overview — Every server at a glance - Offset History — Track drift over time - Offset Histogram — How the offsets are spread - Offset Range — Compare consistency across servers - Round Trip and Offset — See whether network delay moves the offset - Clock Sources — Decode reference clocks (GPS, PPS, Rubidium, Cesium) - IPv4 and IPv6 — Compare one server's two addresses - Rankings — Servers scored by jitter and round-trip time, with the steadiest named HELP IN THE APP What an offset is, why your clock drifts, what UTC and atomic time are, and what each screen shows, explained in the app. For anyone who cares how accurate their time really is, and wants to see the difference, not just trust it. Also on Apple TV. FOR TIMEKEEPERS: TRUEOFFSET FOR MAC Run your own time servers? The Mac app, free in this same listing, reads what they record about themselves and charts it, from six hours to a year: - NTPsec, ntpd, chrony, linuxptp, gpsd, Safran SecureSync, and Timebeat - Logs from a folder, or collected over SSH every hour, read-only - Offset, frequency, Allan deviation, temperature, peers, PTP, GNSS sky plots, and each machine's real-time clocks - Restarts, steps, and holdover found and marked, not averaged in - Your servers compared side by side as a fleet More at trueoffset.app/timekeepers --- In appreciation of Emerald Sequoia's Emerald Time.
CUE! Time Signal Sync
This app provides highly accurate time synchronization using NTP, offering visual and auditory cues for precise second-level timing. It's ideal for professionals who need to catch exact moments, such as during events, filming, or technical work.
- NTP-based time correction
- 57/58/59/00-second countdowns
- Signal sounds and haptics
- Voice announcements
- Landscape display mode
- Display dimmer and keep-awake mode
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Make every 00-second moment easier to catch. CUE! is a time signal app designed for timer setup and field time checks. With NTP-based time correction, 57/58/59/00-second countdowns, signal sounds, haptics, and voice announcements, CUE! helps you catch the exact 00-second moment. It is useful for temporary illumination timer panels, facility equipment, electrical work, lighting and audio systems, events, exhibitions, filming, streaming, stage work, live shows, store displays, and any situation where second-level timing matters. ■ CUE!’s Time Correction Logic CUE! is not a clock that simply displays the result of a single NTP request. NTP responses can vary depending on network routes, congestion, Wi-Fi, mobile networks, and device conditions. CUE! collects multiple NTP samples during startup and manual sync, checking each sample’s round-trip time (RTT) and time offset. Slow responses and offset outliers are filtered out. CUE! prioritizes stable samples. The selected NTP time is linked to the device’s monotonic clock at the moment it is received. After that, the in-app time display advances by adding elapsed monotonic time to the NTP reference. During automatic sync, CUE! may keep the previous NTP reference instead of applying a low-confidence result. This helps prevent sudden jumps caused by unstable network responses. ■ 57/58/59/00-Second Cues CUE! starts its countdown at 57 seconds every minute. 57 sec: 3 seconds before 58 sec: 2 seconds before 59 sec: 1 second before 00 sec: CUE! At 00 seconds, the time and cue display change color, making the exact moment easy to recognize visually. It helps when setting timer panels, checking lighting and audio timing, starting streams or recordings, managing events, and confirming 00-second timing in the field. ■ Sound, Haptics, and Voice CUE! can notify you at 57/58/59/00 seconds with signal sounds and haptics. Signal sound can be turned on or off. Use sound when allowed, or turn it off and rely on the display and haptics. Haptics use different patterns for warning seconds and the exact 00-second cue. Haptics can also be turned on or off. Voice announcements help you understand timing even when your iPhone is in your pocket. Choose announcements every 1 minute, 15 minutes, 30 minutes, or 1 hour. CUE! supports English, Japanese, Simplified Chinese, Traditional Chinese, and Korean. Other languages fall back to English. ■ Landscape Display Turn your iPhone sideways to use a larger clock display. This is useful when placing your iPhone on a stand, near a lighting console, audio mixer, or timer panel. ■ Field Features CUE! includes: ・Display dimmer ・Keep-awake mode ・Rear flashlight control ・Cue color toggle ・Haptics ON/OFF ・Signal sound ON/OFF ・Portrait and landscape layouts ・Remove ads option ■ Recommended For ・Temporary illumination timer setup ・Facility equipment time setting ・Electrical work and field timing ・Lighting and audio timing checks ・Events, exhibitions, stages, and live shows ・Streaming, recording, and filming start cues ・Store display and timer control checks ・Checking every 00-second moment clearly ・Using a clock that always shows seconds ・NTP-based time checking CUE! is a field time signal app that supports the exact “now.” ■ Free to Use CUE! is free to download. Banner ads are shown in the app. To avoid interrupting important timing moments, CUE! does not use interstitial ads. You can remove banner ads with an in-app purchase. ■ Notes CUE! uses public NTP servers to support its in-app time display. However, differences may occur due to network conditions, device status, screen rendering, audio output, haptics, speaker latency, or Bluetooth device latency. CUE! does not guarantee millisecond-level synchronization, measurement accuracy, broadcast timing, or legal proof of time. However, it can be a useful support tool for timer setup, 00-second alignment, and second-level time checks in field environments.
Screenshots
Verdict
The clearest difference is in-app purchases: TrueOffset at none against CUE! Time Signal Sync's 1. TrueOffset also leads on ads (none vs shown). On price, review sentiment, update cadence and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. CUE! Time Signal Sync sells 1 one-off in-app purchase. TrueOffset asks for nothing beyond the download.
TrueOffset ships an update fortnightly, CUE! Time Signal Sync every 8 days. Both last shipped on November 5, 2026.
| Parameter | TrueOffset | CUE! Time Signal Sync |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (9 ratings) — better | — |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 9 — better | — |
| Update frequency | Fortnightly | Every 8 days — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, Apple TV — better | iPhone, iPad |
| Requires iOS | 17.6 | 17.6 |
| Further details — not scored | ||
| Size | 4 MB | 6 MB |
| Age rating | 4+ | 4+ |
| Developer | Richard Bollar | TAKAO OGASAWARA |
Customer experience
TrueOffset
CUE! Time Signal Sync
In-app purchases
TrueOffset
No in-app purchases
CUE! Time Signal Sync
- Remove Ads$2.99
Questions
Is TrueOffset free?
Is CUE! Time Signal Sync free?
Do TrueOffset or CUE! Time Signal Sync have ads?
Which is updated more often, TrueOffset or CUE! Time Signal Sync?
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