Comparison

iJishin vs J

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

Head to head
About

iJishin

This application transforms your iPhone into a seismometer, allowing you to measure and analyze seismic vibrations. You can upload your observations to share with the public and utilize various tools for wave analysis, including graphical displays of power spectrum and displacement.

Highlights
  • Transforms iPhone into a seismometer
  • Measures seismic vibrations
  • Analyzes wave data
  • Uploads seismic observations
  • Graphical display of power spectrum
  • Measures velocity and displacement
Features
Read full description

iJishin – iPhone seismometer, anytime anywhere, measure and browse. iJishin is a free application that makes your iPhone(iPad, iPod touch) change into a seismometer and a data browser as well as a vibration analyser. You can upload seismic information such as maximum acceleration, “SHINDO”(seismic intensity) , occurrence time, and so on, to open your observation to the public. Please visit: http://www.geonavi.com:8888/ iJishin also provides you an excellent tool to measure acceleration anytime anywhere on any occasion. Feel vibration and measure with iJishin! FEATURES: iJishin draws full ability as a seismometer from iPhone(iPad, iPod touch). Also it provides tools for wave analysis. iJishin uses acceleration sensors installed in iPhone(iPad, iPod touch) to measure earthquake vibrations. Signals of three sensors of the device are sampled with frequency of 100Hz and are given the time stamp every 0.01 sec strictly synchronized with UTC by using outer NTP server. iJishin’s recording process starts/stops when the signal becomes larger/smaller than the triggering level. Allowance durations of the process can be set to save data before/after the signal grows/attenuates to the threshold triggering level. iJishin provides you several tools to display and to analyze quake data saved in your iPhone(iPad, iPod touch): not only a wave browser but also a graphical display of power spectrum, of integration such as velocity and displacement, and of the 2D trajectory of the device.

About

J

This app provides official earthquake hazard maps for Japan, allowing users to view predictions of ground shaking intensity. It offers detailed information based on location and displays fault lines and seismic activity models.

Highlights
  • View national earthquake hazard maps
  • Zoom, pan, and adjust map transparency
  • Display probabilistic seismic hazard maps
  • Show surface and deep ground maps
  • View earthquake source fault locations
  • Display seismic activity models
  • Show location-specific earthquake probabilities
Features
Read full description

地震ハザードステーションJ-SHISの公式アプリケーションです。 J-SHISは全国地震動予測地図を表示するiPhone/iPad用公式アプリケーションです。J-SHISを手軽にスマートフォンで見ることができます。 ○全国地震動予測地図※の表示○ 現在公開している最新の全国地震動予測地図を表示することができます。地図は拡大・縮小、移動、透過率の変更を行うことができます。 ・確率論的地震動予測地図(30年震度6強以上となる確率) ・確率論的地震動予測地図(30年震度6弱以上となる確率) ・確率論的地震動予測地図(30年震度5強以上となる確率) ・確率論的地震動予測地図(30年震度5弱以上となる確率) ・長期間平均ハザード(再現期間10万年相当) ・表層地盤地図 ・深部地盤地図 ・想定地震地図 ※「全国地震動予測地図」は、将来日本で発生する恐れのある地震による強い揺れを予測し、予測結果を地図として表したものです。 ○GPSを利用した現在位置周辺の表示○ 地図表示範囲をGPSを利用して現在位置周辺にすることができます。 ○地点情報の表示○ 指定した地点で30年間に震度6弱以上の揺れに見舞われる確率や、表層地盤増幅率、地震ハザードカルテを表示することができます。 ○震源断層の位置と地震活動モデルの表示○ 地図上に主要活断層帯の位置・形状を表示することができます。震源断層をタップすると地震活動モデル(平均ケース)を表示します。

Screenshots

iJishin4 screens
J4 screens

Verdict

The call

The clearest difference is review sentiment: iJishin at 70% against J's 33%. iJishin also leads on update cadence (every 3 months vs every 13 months). On price, ads, in-app purchases and monetization model 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

iJishin ships an update every 3 months, J every 13 months. The most recent releases landed on October 21, 2026 and October 24, 2026 respectively.

Scorecard2 real differences · 8 level
iJishin versus J: the parameters behind the verdict, then further details
ParameteriJishinJ
PriceFreeFree
Rating1.0 (1 ratings) — better—
Positive reviews70.0% of reviews — better33.3% of reviews
Number of ratings1 — better—
Update frequencyEvery 3 months — betterEvery 13 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.615.0 — better
Further details — not scored
Size21 MB9 MB
Age rating4+4+
DeveloperHakusan CorporationNational Research Institute for Earth Science and Disaster Prevention

Customer experience

iJishin

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews30 reviews
Positive70.0%
Neutral10.0%
Negative20.0%

J

Written reviews9 reviews
Positive33.3%
Neutral22.2%
Negative44.4%

In-app purchases

None

iJishin

No in-app purchases

None

J

No in-app purchases

Questions

Is iJishin free?
iJishin is free to download, with no in-app purchases.
Is J free?
J is free to download, with no in-app purchases.
Do iJishin or J have ads?
Neither iJishin nor J shows ads.
Which is updated more often, iJishin or J?
iJishin ships an update every 3 months, and J every 13 months. Most recently, iJishin was updated on October 21, 2026 and J on October 24, 2026.

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