NTP Inspector vs TrueNTP

NTP Inspector is an application that allows you to check servers running the NTP protocol over the Internet and report some basic information. It sends an NTP packet from your device to the server and reports backs almost everything included in the response, like the protocol version, mode, the server Stratum, its precision, reference time, as well as whether there is a leap second today or not. With this app you can troubleshoot NTP servers from anywhere, as seen from your device, and not a remote server, with complete privacy. The app was created when I received an alert for one of my NTP pool servers while outside and without laptop access, with no other option to query it to see what's wrong.

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 • Turn your phone on its side for a full-screen clock face that stays awake, ready to prop up as a reference • On iPhone Duo: a larger clock when open, and the clock above the fold with the servers below when it stands half folded • 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.