WilhelmSK vs Cortex Onboard
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
WilhelmSK
This app provides a customizable dashboard for monitoring and controlling boat systems. It integrates with various marine electronics and offers features like alarm notifications, autopilot control, and chart display.
- Customizable display and monitoring dashboard
- Integrates with Signal K Server and various marine devices
- Autopilot control and monitoring
- Active Captain Points of Interest display
- Alarms and push notifications
- Navionics chart display
- Customizable gauges and layouts
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WilhelmSK is a highly customizable display, monitoring and control dashboard for your boat. WilhelmSK works best wth Signal K Server . It can also connect directly to some devices: º NMEA 0183 over TCP or UDP. (from for example, Digital Yacht's Smart WLN10) º Any modern Navico (Lowrance, Simnet or B&G) GoFree MFDs º NMEA 2000 via Yacht Device's YDWG-02, YDEN º NMEA 2000 via Actisense W2k-1 or W2K-2 º Victron Venus GX or CCGX º Victron VRM º Chetco SeaSmart Devices º Chetco HelmSmart RayMarine and Simrad/B&G Auto Pilot Support (via node-server or the YDWG only, W2K-1) º View or change current mode º View current target heading or Wind direction º Change target heading or Wind direction Alarms and Notifications º View list of current current alarms º Push notification support * º Setup server side alarms * º Set an anchor alarm with the push of a button * Navionics Maps If you already have the Navionics Boating application with an active subscription, you can now use the same Navionics charts in WilhelmSK. Ensure you are a registered user with Navionics and have a Username and Password. If you have not registered, go to the Navionics Boating App’s Main Menu, click on the top “Me” option and then click Login. In WilhelmSK click the login button on the bottom right of the map and enter your Navionics login information. Features: - Raymarine MFD: display and interact with a RayMarine MFD (discovered via Bonjour) - Fusion stereo (control zone volumes, source input, play, pause etc.) - Create a gauge for any value available via SignalK - Sophisticated anchor alarm (requires node server and signalk-anchoralarm-plugin) - Customize gauge display using SignalK meta.zones - Customize gauge range, min/max, etc. - Save custom gauges to node server or the cloud for use on other devices - Wind Angle gauges can optionaly be rotated so that they always point ot the bow of the boat, regaurless of device positioning - Place gauges by long pressing on a gauge and choosing a differnt one - Make a gauge full screen by double tapping - Multiple layout support. Create a differnt layout for Steaming, Sailing, Home Monitoring, etc. - Customize the nuber of pages and their layout - Manuall connection configuration synced accross devices via iCloud - Automatic connection selection based on current ip (usefull when Bonjour is not available and you have multiple boats) - Two themes, dark and light - Animated gauge needles - iPad Slideover and Split View support (Your gauge configuration can be customized for these views) - Connections can be configured to be refreshed manually or at a specific time interval - Design your own custom gauge templates - Share your custom templates via Air Drop, eMail, Text, etc. - Edit ApplyTV or other device layouts and templates remotely using your iPhone or iPad - Most gauges can be configured to be digital or analog - Enter the SignalK path and title for any gauge to show data not supported by default - Displays AIS targets in the Map views - Configure node server plugins inside of the app - IP and RTSP camera display * Some advanced features require signalk-server-node and special plugins installed. Setup Instructions at https://github.com/sbender9/wilhelmsk-node-server-setup
Cortex Onboard
This app allows you to configure and update your marine electronics from your mobile device. Monitor vessel data, receive alerts, and manage features like Anchor Watch from anywhere on board.
- Configure and update Cortex devices
- View AIS information and alerts
- Manage Anchor Watch
- Monitor vessel sensors
- Connect NMEA 2000 instruments
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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).
Screenshots
Verdict
The clearest difference is price: Cortex Onboard at Free against WilhelmSK's $19.99. WilhelmSK's advantage is rating (4.5 vs 3.8) and review sentiment (80% vs 56%). On ratings volume, update cadence, ads and in-app purchases 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; WilhelmSK costs $19.99 up front. Neither carries in-app purchases, so what you see is what you pay.
WilhelmSK holds the better App Store score, 4.5 against 3.8. Both are backed by a comparable volume of ratings — 28 and 12 respectively. Written reviews point the same way: 80% of WilhelmSK's written reviews are positive against 56% of Cortex Onboard's.
Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 11, 2026 and June 7, 2026 respectively.
| Parameter | WilhelmSK | Cortex Onboard |
|---|---|---|
| Price | $19.99 | Free — better |
| Rating | 4.5 (28 ratings) — better | 3.8 (12 ratings) |
| Positive reviews | 80.0% of reviews — better | 55.6% of reviews |
| Number of ratings | 28 — better | 12 |
| Update frequency | Every 2 months | Every 2 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod, Apple TV, Apple Watch — better | iPhone, iPad, iPod |
| Requires iOS | 13.0 — better | 15.6 |
| Further details — not scored | ||
| Size | 118 MB | 376 MB |
| Age rating | 4+ | 4+ |
| Developer | Scott Bender | Garmin New Zealand Ltd |
Customer experience
WilhelmSK
Cortex Onboard
In-app purchases
WilhelmSK
No in-app purchases
Cortex Onboard
No in-app purchases









