TrueOffset vs TrueNTP
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
TrueOffset
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TrueOffset is a precision time utility for comparing time sources and measuring clock offset with clarity and confidence. Compare multiple Network Time Protocol (NTP) servers, visualize the difference between them, and see how your device's clock aligns with selected references. A clean, instrument-style interface presents time as a measurement—focused on accuracy, not decoration. FOUR 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 UTC & TAI TIME SCALES Display Coordinated Universal Time (UTC) and International Atomic Time (TAI) alongside your local time. UTC and TAI feature authentic deadbeat second hands that step crisply to each second, visually distinct from the smooth-sweep local time. TAI runs 37 leap seconds ahead of UTC—see both atomic time scales at a glance. 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 six classic signals synthesized to their published pitch and timing: Six Pips (Greenwich Time Signal), WWV, WWVH, CHU, Jihō, and Moscow Six Pips. 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. 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. PRECISION VISUALIZATION The NTP Offset view displays two second hands: your device clock (gray) and true NTP time (green). The offset magnifier shows drift on a ±10ms scale, so you can see sub-millisecond accuracy at a glance. DUAL-STACK COMPARISON A feature no other NTP app offers: compare IPv4 and IPv6 paths to the same server. Detect DNS misconfigurations, identify when address families route to different servers, and verify your network is delivering consistent time on both stacks. FLEXIBLE TIME SOURCES Compare against Apple, Google, Cloudflare, NIST, US Naval Observatory, global NTP pools, or add your own servers. Set any source as your reference and track offsets across all configured servers. QUALITY ANALYTICS Eight swipeable chart pages reveal the character of your time sources: - Dashboard — Sparkline overview of all servers - Offset History — Track drift over time - Histogram — Offset distribution analysis - Box Plot — Compare consistency across servers - RTT Scatter — Correlate latency with offset - Clock Sources — Decode reference clocks (GPS, PPS, Rubidium, Cesium) - Dual-Stack — IPv4 vs IPv6 path comparison - Rankings — Servers scored by jitter and round-trip time TrueOffset is designed for users who care about how accurate their time really is—and want to see the difference, not just trust it. --- In appreciation of Emerald Sequoia's Emerald Time.
TrueNTP
This app precisely measures your phone's clock against true time by querying multiple servers and calculating a corrected time with millisecond accuracy. It displays the corrected time, your device's drift, and an uncertainty figure, making it useful for network verification and anyone needing accurate time.
- Precise time measurement
- Cross-checks multiple time servers
- Displays device clock drift
- Shows measurement uncertainty
- Customizable server presets
- Offset timeline visualization
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TrueNTP measures how far your phone's clock is from true time. It queries multiple independent time servers, cross-checks their answers, and computes a corrected time with millisecond precision. You see the corrected time, your device clock's drift, and an uncertainty figure so you know how much to trust the number. WHO IT'S FOR Network admins verifying NTP infrastructure. Cell techs checking tower timing. Sysadmins chasing certificate and Kerberos clock-skew errors. IT teams resyncing air-gapped and offline systems: hold the phone next to the console and set the clock from a known-good reference. And anyone curious what time it actually is. HOW IT MEASURES • Bursts of SNTP samples to every active server, weighted by network quality (1/RTT) • Per-server offset, round-trip time, and stratum at a glance • Optional outlier rejection against the cross-server median • Six curated presets (Apple, Cloudflare, NIST, Google, Microsoft, Amazon). Enable any of them or add your own • An uncertainty readout alongside every measurement WHAT YOU SEE • A large clock showing corrected time, ticking smoothly, unaffected by OS clock changes • Device clock card: your clock's drift, labeled plainly as DEVICE AHEAD, DEVICE BEHIND, or IN SYNC • Server list with per-server detail sheets: refid, root delay, root dispersion, per-sample scatter • 30-minute offset timeline showing your clock's behavior PRIVACY No accounts, no analytics, no tracking. Settings and history stay on your device. The privacy policy is one page. A short, plain-language NTP guide is included.
Screenshots
Verdict
The clearest difference is in-app purchases: TrueOffset at none against TrueNTP's 1. TrueOffset also leads on ads (none vs shown) and ratings volume (7 vs 1). TrueNTP's advantage is iOS requirement (15.0 vs 17.6). On price, rating, review sentiment 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. TrueNTP sells 1 one-off in-app purchase. TrueOffset asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 4.9 for TrueOffset against 5.0 for TrueNTP. That said, the two scores are not equally well evidenced: TrueOffset has 7 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.
| Parameter | TrueOffset | TrueNTP |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (7 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 7 — better | 1 |
| Update frequency | Every 3 weeks | — |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad, Apple TV | iPhone, iPad, iPod |
| Requires iOS | 17.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 2 MB | 33 MB |
| Age rating | 4+ | 4+ |
| Developer | Richard Bollar | Brett Herman |
Customer experience
TrueOffset
TrueNTP
In-app purchases
TrueOffset
No in-app purchases
TrueNTP
- Pro Unlock$3.99








