UTC Orbit vs On
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
UTC Orbit
This utility converts between human-readable dates and a YYDDD.FFFFFF format essential for spacecraft orbital element calculations. It also features a UTC alarm clock based on the day of the year and a large digit UTC display.
- UTC time conversion
- YYDDD.FFFFFF format display
- UTC alarm clock
- Day of Year alarm setting
- Large digit UTC clock display
- Background alarm notifications
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UTC Orbit; is a time conversion utility for use with Earth orbital elements calculations for spacecraft. The application also contains a UTC alarm clock that is based on "Day of Year". UTC stands for "Universal Time Coordinated", but is also known as Zulu Time or GMT Time. The application allows the user to select any epoch time in the future or past via pick wheels and that time is then displayed as YYDDD.FFFFFF where YY=Two digit year, where DDD=day of the year (000 - 366), and where .FFFFFF is the decimal fraction of the day. This is the standard format for manipulation of spacecraft tracking TLE's (Two Line Element sets). The app also works in reverse where the user types in the epoch time and the pick wheels will spin to the human readable date. The alarm is set via the pick wheels and operates in the background for sound and screen notification as well as the foreground if application is running. The user must "allow notifications" for the background to function. A useful feature of the app is that if you rotate the iPhone you then have a large digit UTC clock. iPad large digit clock is selected by touching the button "UTC screen". Note that this locks the screen rotation on all devices and to return to the calculation screen you must touch "Back to main screen".
On
This tool assists amateur radio operators with managing on-air nets and check-ins. It offers real-time messaging, email integration, and detailed operator information retrieval. The app supports multiple simultaneous sessions and configurable displays for efficient communication and tracking.
- Real-time net check-in tracking
- Instant messaging (AIM) sessions
- Integrated email client
- Configurable information displays
- QRZ/QRZCQ call sign lookup
- WebSDR audio streaming
- QRZ Logbook integration
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On-Air Net Scraper "Personal" Pro is an iPhone/iPad/MacOS silicon App providing a wide range of features for Amateur Radio operators (Hams). Key features include NetLogger Amateur Radio On-Air Nets, Check-Ins and multiple Almost Instant Message (AIM) sessions in real-time data awareness. AIM pass key automatic email request with single button click resulting in immediate pass key information reply. Full integrated Email client for yet another method for Hams to carry out conversations. Multiple tabbed displays allowing user to track unlimited number of On-Air Net Check-Ins at one time. User configurable information displays to included viewing detailed Ham information within Check-In views. Near real-time AIM client text message send and receive. Searching and viewing Past NetLogger Nets and Check-Ins. Monitor mode so users can be aware of NetLogger Check-In "lurkers". Simultaneous QRZ and QRZCQ login is supported facilitating Call Sign lookup and Ham information retrieval. Easy, click to display NetLogger Nets, Check-Ins Call Sign and operator status information, not requiring QRZ/CQ accounts. Multi-screen displays to included improved 2-way and 3-way split screens provide simultaneous displays of Check-Ins, AIM, AIM and Net Scraper Message Exchange current listing data along with WebSDR viewing and listening. PERSISTENT WebSDR radio LIVE audio listenings while simultaneously viewing multiple Net Check-In views. Seamlessly integrates with On-Air Net Scraper Desktop Server WebSocket Interface supporting private Internet chat sessions between On-Air Net Scraper ME clients. JS8Call/WSJTX full participation in digital radio REAL-TIME texting when using NetBird VPN or when paired with On-Air Net Scraper's Message Exchange (ME) Server. Autoload favorite NetLogger nets. Callsign search both NetLogger Active and Past net listing, including improved automatic continuous search and displaying of matched nets. QRZ Logbook insert/update/delete. Supports On-Device authentication and Two-Factor authentication in addition to encrypted secure storage of sensitive data and app access security. JS8Call dynamic frequency adjustment.
Screenshots
Verdict
The clearest difference is review sentiment: UTC Orbit at 100% against On's 50%. UTC Orbit also leads on rating (5.0 vs 4.4). On's advantage is update cadence (monthly vs every 8 months) and ratings volume (13 vs 2). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.
UTC Orbit holds the better App Store score, 5.0 against 4.4. That said, the two scores are not equally well evidenced: On has 13 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 100% of UTC Orbit's written reviews are positive against 50% of On's.
UTC Orbit ships an update every 8 months, On monthly. The most recent releases landed on October 2, 2026 and October 24, 2026 respectively.
| Parameter | UTC Orbit | On |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) — better | 4.4 (13 ratings) |
| Positive reviews | 100.0% of reviews — better | 50.0% of reviews |
| Number of ratings | 2 | 13 — better |
| Update frequency | Every 8 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 26.0 | 15.6 — better |
| Further details — not scored | ||
| Size | 2 MB | 30 MB |
| Age rating | 4+ | 17+ |
| Developer | Dave Massey | Christopher Robson |
Customer experience
UTC Orbit
On
In-app purchases
UTC Orbit
No in-app purchases
On
No in-app purchases









