ESA Instruments vs SpearfishingSFG
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ESA Instruments
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ESA Instruments is the new App from Astra Yacht that transform your iPhone/iPad in a full function marine display. Connect ESA Instruments to an Astra Yacht GAMP (http://www.astrayacht.com/wp/en/shop/multiplexer-gamp-nmea-0183-esa/) and you can visualize every information coming from the boat instruments. Moreover, if you haven't any electronic instruments on board, you can use ESA Instruments App combined with the Astra Yacht box EBI. EBI has an internal GPS at high speed, and it's able to receive wind data directly from the most popular wind sensors both wired and wireless, and it can be connected to 4 other NMEA 0183 sensors (such as speed-depth sensor, electronic compass, AIS, wind sensor). Data from various sensors can be displayed via Wi-Fi directly on Apple devices through the App ESA Instruments that, in addition to the visualization of data in a very light and flexible way, allows you to easily calibrate your sensors thanks to a user friendly settings procedure. With ESA Instruments you can visualize data in various format: - page with a single data ; - page with two data; - page with tree data; - page with four data; - page with analog wind indicator; - page with GPS data; - page with graphic wind history (5', 10', 20' or 60' time period). in every page you can select the data you want to display in a very simple way.
SpearfishingSFG
This application helps determine optimal weather conditions for spearfishing in Saint Martin. It provides hourly weather snapshots and a basic equipment checklist.
- Optimal weather condition determination
- Hourly weather snapshots
- Basic spearfishing equipment checklist
- Saint Martin specific conditions
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This fun app was designed to determine the proper weather conditions to spearfish on the island of Saint Martin. Hourly snapshots of weather conditions from preselected indicators along with basic spearfishing equipment check list.
Screenshots
Verdict
The clearest difference is update cadence: SpearfishingSFG at every 3 months against ESA Instruments's every 6 months. ESA Instruments's advantage is device support (3 vs 1) and iOS requirement (15.6 vs 18.0). On price, 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
ESA Instruments ships an update every 6 months, SpearfishingSFG every 3 months. The most recent releases landed on October 16, 2026 and October 19, 2026 respectively.
| Parameter | ESA Instruments | SpearfishingSFG |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | Every 6 months | Every 3 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 18.0 |
| Further details — not scored | ||
| Size | 3 MB | 2 MB |
| Age rating | 4+ | 17+ |
| Developer | Astra Yacht | Terrance Baptiste |
In-app purchases
ESA Instruments
No in-app purchases
SpearfishingSFG
No in-app purchases
Questions
Is ESA Instruments free?
Is SpearfishingSFG free?
Do ESA Instruments or SpearfishingSFG have ads?
Which is updated more often, ESA Instruments or SpearfishingSFG?
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