TrueOffset vs PDF Redactor
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
Read full descriptionHide full description
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.
PDF Redactor
Permanently hide sensitive information in PDF documents by drawing black boxes over text or content. Export a flattened PDF where redactions are irreversible, ensuring privacy before sharing. This utility works offline and focuses on quick, straightforward redaction without complex editing tools.
- Permanently redact sensitive information
- Draw black redaction boxes
- Export flattened, irreversible PDFs
- Works fully offline
- Simple, one-time redaction tool
Read full descriptionHide full description
PDF Redactor makes it easy to permanently hide sensitive information in PDF documents — privately, right on your iPhone. Whether you're sharing a document, removing personal details, or protecting confidential information, PDF Redactor helps you create a safer copy in just a few taps. REDACT TEXT AND DOCUMENT AREAS Tap to redact specific text or draw black boxes over any part of your PDF. Move, resize, or remove redactions before exporting. FIND SENSITIVE INFORMATION Automatically identify potential sensitive information, such as email addresses, phone numbers, addresses, and dates. Review the suggestions and choose exactly what to redact. OPEN AND SHARE PDFs EASILY Open PDF documents directly from the iPhone Share menu, make your redactions, and share the finished PDF using your favorite apps. PERMANENT REDACTION Export a flattened PDF with redactions baked into the document. The original text beneath covered areas is not preserved as a removable text layer. PRIVATE AND OFFLINE Your documents are processed directly on your device. No accounts, no uploads, and no internet connection required. FEATURES • Tap to redact text • Draw and adjust redaction areas • Find and review sensitive information • Undo, move, resize, and remove redactions • Open PDFs from other apps • Share permanently redacted PDF files • Keep your original PDF unchanged • Work entirely offline PDF Redactor is designed for fast, straightforward PDF redaction — without subscriptions, accounts, or complicated editing tools.
Screenshots
Verdict
The clearest difference is review sentiment: TrueOffset at 100% against PDF Redactor's 0%. TrueOffset also leads on price (Free vs $1.99) and rating (5.0 vs 1.0). On ads, in-app purchases and iOS requirement 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
TrueOffset is free to download; PDF Redactor costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
TrueOffset holds the better App Store score, 5.0 against 1.0. That said, the two scores are not equally well evidenced: TrueOffset has 9 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of TrueOffset's written reviews are positive against 0% of PDF Redactor's.
TrueOffset ships an update fortnightly, PDF Redactor every 4 months. Both last shipped on November 5, 2026.
| Parameter | TrueOffset | PDF Redactor |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 5.0 (9 ratings) — better | 1.0 (1 ratings) |
| Positive reviews | 100.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 9 — better | 1 |
| Update frequency | Fortnightly — better | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad, Apple TV — better | iPhone |
| Requires iOS | 17.6 | 17.6 |
| Further details — not scored | ||
| Size | 4 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Richard Bollar | OpsOh LLC |
Customer experience
TrueOffset
PDF Redactor
In-app purchases
TrueOffset
No in-app purchases
PDF Redactor
No in-app purchases









