Cortex Onboard vs EZ Sextant
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Cortex Onboard
Configure and update your marine electronics, and monitor vital boat data remotely. Receive alerts, view AIS information, and manage anchor watch from your mobile device.
- Configure and update Cortex devices
- View AIS information and alerts
- Manage Anchor Watch remotely
- Monitor boat sensors and NMEA 2000 instruments
- View battery, pressure, and position data
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Cortex Onboard is free with your Cortex. Use it to configure your Cortex Hub and download updates to your Cortex devices with new features and improvements. You can also use Cortex Onboard to receive and manage alerts, view AIS information and instrument data anywhere on board your boat. View out-of-the-box sensors or NMEA 2000 networked instruments. - Setup is easy and free. - Use Cortex Onboard to configure and update your Cortex devices easily. - View AIS information and receive alerts on board direct to your device. - Manage Anchor Watch from the palm of your hand anywhere on board. - Use the Cortex Hub’s built-in sensors for battery level, barometric pressure and boat position. - Connect your Cortex Hub to NMEA 2000, or an external sensor, to add monitoring for wind, depth, bilge high water, temperature, shore power or security. - The Cortex Hub supports up to 10 WiFi devices (includes Handsets).
EZ Sextant
Navigate open waters using your phone's camera to sight celestial bodies. This app plots lines of position and combines them for an estimated location on a lat/lon grid. It's a powerful tool for offshore navigation without relying on GPS.
- GPS-free navigation
- Camera-based celestial sightings
- Automatic position plotting
- Built-in almanac
- Running fix calculations
- Lat/lon grid display
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Navigate in open waters without a GPS. The phone's camera is used to make sightings of the sun, moon, Venus, or Mars. The sighting results are plotted as lines of position with multiple sightings combined into a running fix. Your estimated position is displayed on a lat/lon grid. You can also use your sextant and take advantage of the built-in almanac and plotting tools.
Screenshots
Verdict
The clearest difference is price: Cortex Onboard at Free against EZ Sextant's $24.99. Cortex Onboard also leads on ratings volume (12 vs 4) and iOS requirement (18.5 vs 26.0). EZ Sextant's advantage is review sentiment (100% vs 56%) and rating (5.0 vs 3.8). On ads, in-app purchases 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
Cortex Onboard is free to download; EZ Sextant costs $24.99 up front. Neither carries in-app purchases, so what you see is what you pay.
EZ Sextant holds the better App Store score, 5.0 against 3.8. Both are backed by a comparable volume of ratings — 12 and 4 respectively. Written reviews point the same way: 56% of Cortex Onboard's written reviews are positive against 100% of EZ Sextant's.
Cortex Onboard ships an update every 2 months, EZ Sextant monthly. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.
| Parameter | Cortex Onboard | EZ Sextant |
|---|---|---|
| Price | Free — better | $24.99 |
| Rating | 3.8 (12 ratings) | 5.0 (4 ratings) — better |
| Positive reviews | 55.6% of reviews | 100.0% of reviews — better |
| Number of ratings | 12 — better | 4 |
| Update frequency | Every 2 months | Monthly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 18.5 — better | 26.0 |
| Further details — not scored | ||
| Size | 22 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Garmin New Zealand Ltd | Third Reef Software LLC |
Customer experience
Cortex Onboard
EZ Sextant
In-app purchases
Cortex Onboard
No in-app purchases
EZ Sextant
No in-app purchases
Questions
Is Cortex Onboard free?
Is EZ Sextant free?
Which has better reviews, Cortex Onboard or EZ Sextant?
Do Cortex Onboard or EZ Sextant have ads?
Which is updated more often, Cortex Onboard or EZ Sextant?
Other comparisons
