Comparison

NSJ Tracker vs SailViewer

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

Head to head
About

NSJ Tracker

Features
Read full description

GPS tracker app for yacht racing. Sends real-time position, speed, and course data to the race management server. ヨットレース用GPSトラッカーアプリ。位置・速度・針路データをリアルタイムでレース管理サーバーに送信します。

About

SailViewer

Features
Read full description

SailViewer turns sailing GPS and instrument logs into an interactive debrief on iPhone and iPad. Import a supported sailing file, choose the logs you want to open, and explore the race from several angles: • Track views with boats, courses, selections, and optional map backgrounds • Tables and graphs for comparing selected values • Polar analysis for speed and angle relationships • Start, Race, Boat, and Maneuvers views when supported by the data • Local image sharing from supported analysis windows SailViewer includes synthetic sample logs. Samples start closed, so you decide when to open them. You can import SW2, SLV, GPX, KML, NMEA, VTK, FIT, VKX, supported CSV sources, and supported ZIP archives. Your imported sailing files stay on your device unless you explicitly share them. Ordinary iPhones, including large iPhones, have permanently free local access and do not require weekly license checks. All iPads, including iPad mini, and this iPad app running on an Apple-silicon Mac are free through 31 December 2026. These devices require an internet connection for initial activation and at least once every seven days. Free access ends on 1 January 2027 at 00:00 UTC, when a paid subscription will be required. Purchasing will require a future app update; this release cannot take payments. There is no automatic charge. If access expires, your local library is retained. Optional error reports and usage summaries are off by default. Support reports are sent only when you choose to send them, and original sailing logs are not attached automatically. This is the new SailViewer app and is separate from the legacy SailViewer/TruSailViewer product. Automatic transfer from the legacy app is not promised; keep your original files and import supported formats into this app.

Screenshots

NSJ Tracker4 screens
SailViewer3 screens

Verdict

The call

The clearest difference is update cadence: NSJ Tracker at every 6 days against SailViewer's every 2 weeks. On price, 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

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

NSJ Tracker ships an update every 6 days, SailViewer every 2 weeks. The most recent releases landed on November 10, 2026 and November 7, 2026 respectively.

Scorecard1 real difference · 5 level
NSJ Tracker versus SailViewer: the parameters behind the verdict, then further details
ParameterNSJ TrackerSailViewer
PriceFreeFree
Update frequencyEvery 6 days — betterEvery 2 weeks
AdsNoNo
In-app purchasesNoNo
DevicesiPhoneiPhone, iPad — better
Requires iOS17.617.0 — better
Further details — not scored
Size0 MB51 MB
Age rating4+4+
DeveloperKeita YukinoriMaster Sailing jdoo

In-app purchases

None

NSJ Tracker

No in-app purchases

None

SailViewer

No in-app purchases

Questions

Is NSJ Tracker free?
NSJ Tracker is free to download, with no in-app purchases.
Is SailViewer free?
SailViewer is free to download, with no in-app purchases.
Do NSJ Tracker or SailViewer have ads?
Neither NSJ Tracker nor SailViewer shows ads.
Which is updated more often, NSJ Tracker or SailViewer?
NSJ Tracker ships an update every 6 days, and SailViewer every 2 weeks. Most recently, NSJ Tracker was updated on November 10, 2026 and SailViewer on November 7, 2026.

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