Comparison

ESA Instruments vs SpearfishingSFG

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

ESA Instruments

Features
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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.

About

SpearfishingSFG

This application helps determine optimal weather conditions for spearfishing in Saint Martin. It provides hourly weather snapshots and a basic equipment checklist.

Highlights
  • Optimal weather condition determination
  • Hourly weather snapshots
  • Basic spearfishing equipment checklist
  • Saint Martin specific conditions
Features
Read full description

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

ESA Instruments4 screens
SpearfishingSFG3 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

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.

Scorecard3 real differences · 6 level
ESA Instruments versus SpearfishingSFG: the parameters behind the verdict, then further details
ParameterESA InstrumentsSpearfishingSFG
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 6 monthsEvery 3 months — better
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.6 — better18.0
Further details — not scored
Size3 MB2 MB
Age rating4+17+
DeveloperAstra YachtTerrance Baptiste

In-app purchases

None

ESA Instruments

No in-app purchases

None

SpearfishingSFG

No in-app purchases

Questions

Is ESA Instruments free?
ESA Instruments is free to download, with no in-app purchases.
Is SpearfishingSFG free?
SpearfishingSFG is free to download, with no in-app purchases.
Do ESA Instruments or SpearfishingSFG have ads?
Neither ESA Instruments nor SpearfishingSFG shows ads.
Which is updated more often, ESA Instruments or SpearfishingSFG?
ESA Instruments ships an update every 6 months, and SpearfishingSFG every 3 months. Most recently, ESA Instruments was updated on October 16, 2026 and SpearfishingSFG on October 19, 2026.

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