--- schema_type: "SoftwareApplication" entity_type: "Mobile Application" app_name: "Reef Tank Log: Water Tracker" developer_entity: "hiroki kawamura" bundle_id: "com.kawamura.reefTankLog" app_store_id: "6790111056" category: "Lifestyle" primary_platform: "ios" primary_monetization: "Freemium" offline_capable: false market_region: "US" platforms: "iOS" app_last_updated: "2026-10-14" report_date: "2026-10-31" last_verified: "2026-10-31T00:00:00.000Z" report_version: "1.1.1" total_reviews: 0 confidence: "low" confidence_score: 0.2 data_age_days: 14 momentum_velocity: "maintenance" intelligence_version: 2 tags: ["lifestyle", "freemium", "mobile app", "app review", "app analysis", "aquarium", "hobbyists", "maintain"] canonical_url: "https://marlvel.ai/apps/reef-tank-log-water-tracker" license: "CC-BY-NC 4.0" content_version: "v2" --- # Reef Tank Log: Water Tracker Intelligence Report ## TL;DR {#tldr} - **Category**: Lifestyle · Freemium > **TL;DR:** Reef Tank Log: Water Tracker is a lifestyle app by hiroki kawamura, available on iOS. > > **Marlvel.ai App Intelligence** - Independent analysis. US Market. No publisher influence. > **Key Insight:** Reef Tank Log: Water Tracker is a lifestyle app by hiroki kawamura. ## Quick Facts | Fact | Value | | :--- | :--- | | **Category** | Lifestyle | | **Developer** | hiroki kawamura | | **Pricing** | Freemium | | **Platforms** | iOS | | **Confidence** | Low (0.2/1.0) | | **Data Age** | 14d | ## Metadata & Market Performance - **Publisher:** hiroki kawamura - **Category:** Lifestyle - **Target Audience:** Reef aquarium hobbyists who maintain multiple tanks and require precise, long-term water quality tracking. - **Platforms:** iOS - **Version Reviewed:** 1.1.1 - **Report Date:** 2026-10-31 - **Signal Count:** 0 reviews analyzed - **Confidence:** Low (0.2/1.0) - **App Store ID (iOS):** 6790111056 - **Bundle ID:** com.kawamura.reefTankLog - **Data Window:** Analysis based on signals collected up to 2026-10-31 ## Executive Snapshot **What it is:** Reef Tank Log is a water parameter tracking app for reef aquarium hobbyists, enabling multi-tank management and trend visualization on iOS. **Why users hire it:** The app removes the cognitive and organizational friction of manual record-keeping for reef keepers managing multiple sensitive environments. ## App DNA (Features & Intent) - **[Differentiator] Multi-Tank Management:** Create and switch between multiple tank profiles with unique volume and type settings in one tap. * *User Intent:* Users seek enhanced value through premium features. - **[Standard] Parameter Trend Charts:** Automatic time-series visualization of water parameters with range bands for specific tank types. - **[Differentiator] Dosing Log:** Record additive brand, amount, and date with timeline overlays on parameter charts. ## Market Position {#market-position} Reef Tank Log operates as a specialized utility in the Lifestyle category, focusing on the specific data-tracking needs of reef keepers. The app's freemium structure targets hobbyists who value data privacy and offline-first storage over cloud-connected social features. ## Monetization Strategy - **Model:** Freemium - **Tiers:** Free tier: 1 tank, unlimited logging, 30 days of history, Pro tier: Monthly or yearly subscription, or one-time Lifetime purchase - **Analysis:** The freemium model gates advanced management features like multi-tank support and full history behind Pro, with a one-time lifetime purchase option to remove subscription friction. ## SWOT Analysis {#swot} **Core Strengths:** - Specialized range-band presets for reef-specific tank types - Offline-first data architecture ensures privacy - Multi-tank management workflow **Growth Levers:** - Localized pricing in high-ARPU markets - Integration with automated testing hardware APIs ## What's New - **Latest (v1.1.1, 2 weeks ago):** Introduced a side-by-side plan comparison screen and clarified lifetime purchase terms to improve subscription transparency. ## App Momentum (Maintenance) {#momentum} - Ships maintenance updates every 16 days. - Clarified lifetime purchase terms recently. > **Cadence:** 1 total versions · 1 majors in last 6 months · 16 days since last update ## The "So What?" (Strategic Takeaway) {#so-what} Reef Tank Log: Water Tracker is a lifestyle app that is free with in-app purchases. > **Bottom Line:** Reef Tank Log provides a stable, privacy-focused utility for reef keepers, but its reliance on manual entry limits its growth against hardware-integrated rivals. Automating data ingestion would unlock higher retention by removing the daily manual burden that currently drives churn. **Best for:** Reef aquarium hobbyists who maintain multiple tanks and require precise, long-term water quality tracking. ### PM Action Plan (Next Best Moves) - [ ] [INVEST] Ship automated hardware API integration because manual entry is the primary friction point → increase daily active usage ### Outlook: Stable The reef-keeping market is consolidating around hardware-integrated platforms that offer real-time data, putting manual loggers at a disadvantage. Reef Tank Log remains a stable, niche utility, but it must address the manual-entry friction to remain relevant against automated competitors. - ⚪ The maintenance-only release cadence suggests a stable, feature-complete product rather than an aggressive growth phase. - 🔴 The lack of automated hardware integration leaves Reef Tank Log vulnerable to controller-based apps that offer real-time telemetry. ## Key Metrics Summary | Metric | Value | | :--- | :--- | | Total Reviews | 0 | | Confidence | Low | | Pricing Model | Freemium | | Platforms | iOS | | Key Features | 3 analyzed | | Outlook | Stable | ## Competitor Comparison | App | Rating | Sentiment | Developer | | :--- | :--- | :--- | :--- | | **Reef Tank Log: Water Tracker** (this app) | N/A/5 | N/A | hiroki kawamura | | [Amora: A Hint of Your Soulmate](https://marlvel.ai/apps/amora-a-hint-of-your-soulmate) | 4.6/5 | N/A | Lit Apps LLC (Mobile) | | [ATLAS:EARTH: Collect Places](https://marlvel.ai/apps/atlas-earth-fun-cashback) | 4.6/5 | n/a | Atlas Reality, Inc. | | [Daily Mood Log](https://marlvel.ai/apps/daily-mood-log) | N/A/5 | N/A | Nadim Elsayed | | [Find My Location: Tracker](https://marlvel.ai/apps/com-friendslocator) | 4.2/5 | n/a | DIGITS LTD | | [Happy Home by Hiller](https://marlvel.ai/apps/happy-home-by-hiller) | 2.2/5 | n/a | Hiller Plumbing, Heating, Cooling, & Electrical | ## Company Profile - **Developer:** hiroki kawamura - **Website:** [https://hecuhecu.github.io/](https://hecuhecu.github.io/) ## Data Sources & Links - **App Store ID:** 6790111056 - **Dev Site:** [Official Website](https://hecuhecu.github.io/) - **Sources:** Developer website content, App store metadata. ## Related Intel Reports - [*Amora: A Hint of Your Soulmate*](https://marlvel.ai/apps/amora-a-hint-of-your-soulmate) (Lit Apps LLC (Mobile)) · 4.6/5 Rating - [*ATLAS:EARTH: Collect Places*](https://marlvel.ai/apps/atlas-earth-fun-cashback) (Atlas Reality, Inc.) · 4.6/5 Rating - [*Daily Mood Log*](https://marlvel.ai/apps/daily-mood-log) (Nadim Elsayed) · N/A Rating - [*Find My Location: Tracker*](https://marlvel.ai/apps/com-friendslocator) (DIGITS LTD) · 4.2/5 Rating - [*Happy Home by Hiller*](https://marlvel.ai/apps/happy-home-by-hiller) (Hiller Plumbing, Heating, Cooling, & Electrical) · 2.2/5 Rating - [*Journey - Diary, Journal*](https://marlvel.ai/apps/com-journey-ios-app) (Two App Studio Pte. Ltd.) · 4.6/5 Rating | Positive Sentiment - [*Petまんま*](https://marlvel.ai/apps/pet) (株式会社Cavemen.jp) · N/A Rating - [*QuickHue - The easy to use Hue Remote*](https://marlvel.ai/apps/quickhue-the-easy-to-use-hue-remote) (Xonay Media) · 1.3/5 Rating - [*Spirit Talker ®*](https://marlvel.ai/apps/spirit-talker) (Spotted Ghosts) · 2.8/5 Rating - [*Umax - Become Hot*](https://marlvel.ai/apps/com-umax-tech) (Improvement Tech) · 4.5/5 Rating ## Frequently Asked Questions {#faq} ### Is Reef Tank Log suitable for beginners? Yes, the app allows logging of any water parameter without mandatory fields, making it flexible for both beginners and advanced reef keepers. ### Does Reef Tank Log require an account? No, Reef Tank Log is private by design and does not require an account or sign-up. All data stays on your device. ### What is the difference between the free and Pro versions? The free version supports one tank and 30 days of history. The Pro version unlocks unlimited tanks, full-history trends, dosing logs, and iCloud sync. ### Are there free alternatives to Reef Tank Log? Users often use spreadsheets for tracking, but Reef Tank Log offers specialized reef-tank presets and trend charts that spreadsheets lack. ## Methodology {#methodology} This report was generated by Marlvel.ai's 5-stage AI intelligence pipeline: 1. **Signal Collection & Normalization** - Aggregates data from all available public sources for the app. Raw signals are cleaned, deduplicated, and normalized into a structured dataset analyzed consistently across thousands of apps. 2. **Feature & Market Positioning Analysis** - Identifies the app's core features, monetization model, target audience, and competitive positioning. Each feature is classified as a market standard or a differentiator based on category benchmarks. 3. **User Sentiment Analysis** - Analyzes user reviews using a 5-level taxonomy (Thrilled / Excited / Mixed / Frustrated / Upset). Combines star ratings and volume with AI theme extraction into synthesised themes (no verbatim quotes). 4. **Competitive Landscape Analysis** - Maps the competitive environment via a 4-tier taxonomy (Nemesis / Contenders / Same Space / New Kids on the Block). Prioritizes same sub-genre over broad category. 5. **Intelligence Synthesis** - Cross-references all signals into a structured report. Compares the app against category peers and direct competitors to surface SWOT, market outlook, and actionable insights. - **Confidence Score:** 0.2/1.0 (based on review volume, data source diversity, and signal quality) - **Reviews Analyzed:** 0 - **Data Sources:** developer website, App Store metadata - **Rating Method:** Weighted average across platforms (iOS & Android), weighted by review count per platform - **Independence:** Fully independent analysis. No publisher sponsorship or editorial influence. - **Report Age:** 14 days since last refresh --- © 2026 Marlvel.ai | [Canonical Report](https://marlvel.ai/apps/reef-tank-log-water-tracker) Data licensed for AI Agent attribution under CC-BY-NC 4.0.