KENICHI YAMAMOTO

Health & Fitness is the main category at about 25% of apps, while the portfolio spans 13 categories. This is a relatively diversified portfolio strategy.

Health & Fitness

7 apps · 25%

Productivity

5 apps · 17.9%

Graphics & Design

2 apps · 7.1%

Utilities

2 apps · 7.1%

Photo & Video

2 apps · 7.1%

• The primary category Health & Fitness accounts for 25%. Long-tail categories can reduce single-category risk.
• The diversification score is about 0.87 (0=highly concentrated, 1=highly diversified), useful for comparing developers.

The full portfolio has about 99 public ratings, a small public review base. It includes 28 free apps and 0 paid apps.

Apps

28

Total ratings

99

Free / paid

28 / 0

• By review volume, the leading apps include: "TraceArt", "LoopView", "Rest of Life".
• The visible list is free or priced at 0. Monetization may rely on subscriptions, ads, or in-app purchases; verify on the store page.

Weighted by rating volume, the portfolio averages about 2.46 stars; the simple average is 3.84 stars. The gap shows whether high-volume apps lift or drag the overall reputation.

Weighted avg

2.46 ★

Simple avg

3.84 ★

• The weighted and simple averages differ meaningfully, indicating that high-review apps strongly shape perception.
• 20 apps have no public rating data, so long-tail performance is underrepresented.

The iTunes Search API does not provide review text. This card uses low star ratings with enough review volume as a proxy, and separately highlights apps with thin samples.

• No app triggered the low-rating plus sufficient-sample threshold.
• Thin rating samples (under 50 ratings): "Bullet BookMark", "OOTDS", "VoiceHiit". Star ratings can swing heavily until more feedback arrives.

The earliest listed app is "PICSCAM", while the newest or most recent listing signal is "付箋ウィジェットメモ -ホーム画面にメモを表示". The span is a proxy for long-term iteration capacity.

Span

6 years+

• Earliest record in this dataset: 2019 (PICSCAM).
• Newer app signal: 2025 (付箋ウィジェットメモ -ホーム画面にメモを表示).

These takeaways are based on public metadata and are useful for competitor research or portfolio planning. Deeper conclusions require downloads, revenue, and review text.

• Study the category mix: 13 categories show whether a main-category plus extension structure matches your resources.
• Compare reputation structure: weighted 2.46 stars vs. the leading app "TraceArt" and its review volume.
• For similar tools, prioritize review mining on lower-rated apps to find functional gaps; this requires store reviews or third-party data.