---
schema_type: "SoftwareApplication"
entity_type: "Mobile Application"
app_name: "Clear Sky Calculator"
developer_entity: "Apogee Instruments"
bundle_id: "com.apogeeinstruments.Clear-Sky"
app_store_id: "974693728"
category: "Business"
primary_platform: "ios"
primary_monetization: "Free"
offline_capable: false
market_region: "US"
platforms: "iOS"
app_last_updated: "2021-09-28"
report_date: "2026-08-23"
last_verified: "2026-08-23T00:00:00.000Z"
report_version: "2.0.5"
total_reviews: 2
overall_rating: 5
sentiment: "Thrilled"
sentiment_score: 90
confidence: "medium"
confidence_score: 0.4
top_praise_theme: "Versatile measurement tools allow users to evaluate small solar charging systems beyond standard instrument calibration"
review_sample_size: 1
total_review_count: 1
analyzed_review_count: 1
data_age_days: 38
momentum_velocity: "zombie"
intelligence_version: 3
tags: ["business", "free", "thrilled sentiment", "mobile app", "app review", "app analysis", "researchers,", "agricultural", "scientists,"]
canonical_url: "https://marlvel.ai/apps/clear-sky-calculator"
license: "CC-BY-NC 4.0"
content_version: "v2"
---

# Clear Sky Calculator Intelligence Report

## TL;DR {#tldr}

- **Category**: Business · Free
- **Signal**: Rating 5 · Sentiment Thrilled
- **Recent focus**: Versatile measurement tools allow users to evaluate small solar charging systems beyond standard instrument calibration (top praise)

> **TL;DR:** Clear Sky Calculator is a business app by Apogee Instruments, rated 5/5 by 2 users, with Thrilled user sentiment (90/100), available on iOS.
>
> **Marlvel.ai App Intelligence** - Independent analysis. US Market. No publisher influence.

<!-- speakable-start -->
> **Key Insight:** Clear Sky Calculator maintains Thrilled user sentiment (5/5 from 2 reviews), with users consistently praising versatile measurement tools allow users to evaluate small solar charging systems beyond standard instrument calibration.
<!-- speakable-end -->

## Quick Facts

| Fact | Value |
| :--- | :--- |
| **Rating** | 5/5 (2 reviews) |
| **User Mood** | Thrilled |
| **Category** | Business |
| **Developer** | Apogee Instruments |
| **Pricing** | Free |
| **Platforms** | iOS |
| **Confidence** | Medium (0.4/1.0) |
| **Data Age** | 38d |

## Metadata & Market Performance
- **Publisher:** Apogee Instruments
- **Category:** Business
- **Target Audience:** Researchers, agricultural scientists, and technicians who manage and maintain solar radiation and quantum sensor networks.
- **Platforms:** iOS
- **Version Reviewed:** 2.0.5
- **Report Date:** 2026-08-23
- **Signal Count:** 1 review analyzed
- **Confidence:** Medium (0.4/1.0)
- **App Store ID (iOS):** 974693728
- **Bundle ID:** com.apogeeinstruments.Clear-Sky
- **Performance Trend:** Stable
- **Data Window:** Analysis based on signals collected up to 2026-08-23

<!-- section:executive-snapshot -->
## Executive Snapshot
**What it is:** Clear Sky Calculator is a technical utility for researchers and agricultural scientists to estimate solar radiation and validate sensor accuracy on iOS.
**Why users hire it:** The tool removes the need for expensive secondary reference equipment by providing a modeled clear sky baseline for sensor recalibration.
<!-- /section:executive-snapshot -->

<!-- section:features -->
## App DNA (Features & Intent)
- **[Standard] Solar Radiation Estimation:** Calculates incident solar radiation intensity on horizontal surfaces using site-specific elevation, latitude, and longitude data.
- **[Differentiator] Sensor Recalibration Monitoring:** Compares real-time sensor readings against modeled clear sky values to determine if sensors require recalibration.
  * *User Intent:* Users expect intelligent, adaptive experiences that learn from their behavior.
<!-- /section:features -->

<!-- section:market-position -->
## Market Position {#market-position}

Clear Sky Calculator serves a specialized B2B-adjacent audience within the Business category, maintaining a 5.0-star rating across its limited user base. The lack of updates since 2021 positions the tool as a static reference utility rather than a competitive market entrant.
<!-- /section:market-position -->

## Monetization Strategy
- **Model:** Free
- **Tiers:** Free
- **Analysis:** The utility is provided as a free service to support the manufacturer's hardware ecosystem and service pipeline.

<!-- section:sentiment -->
## 🟢 User Sentiment (Medium Confidence: 1 of 1 review analyzed) {#user-sentiment}
- **Overall Rating:** 5/5
- **Platform Split:** iOS 5.0/5 (2 ratings)
- **Overall Sentiment:** Thrilled

### Top Praises
- **Versatile measurement tools allow users to evaluate small solar charging systems beyond standard instrument calibration**

<!-- /section:sentiment -->
<!-- section:swot -->
## SWOT Analysis {#swot}

**Core Strengths:**
- Physics-based modeling provides a verifiable accuracy baseline for sensor recalibration.
- Integration with ASCE Standardized Reference Evapotranspiration equations ensures technical alignment with industry-standard research workflows.

**Growth Levers:**
- Expanding the tool to support automated sensor-drift alerts could increase the frequency of user engagement.


<!-- /section:swot -->
## Recent Changes (v2 → v3) {#recent-changes}

The application remains in a static maintenance state with no functional changes. The intelligence update reflects a more granular definition of the app's scientific methodology and its competitive vulnerability to modern cloud-integrated platforms.

**Overall trend**: Stable
**Compared at**: 2026-08-23

### Medium-impact changes
- **[Added] ASCE Methodology Integration** (swot)
- **[Added] Cloud-Integrated Threat Identification** (swot)
- **[Shifted] B2B-Adjacent Positioning** (positioning)

<!-- section:whats-new -->
## What's New

- **Latest (v2.0.5, 4 years ago):** Added ePAR option to the application.
<!-- /section:whats-new -->

<!-- section:momentum -->
## App Momentum (Zombie) {#momentum}

- Maintenance-mode status since late 2021.
- No feature updates in 58 months.

> **Cadence:** 1 total versions · 1 majors in last 6 months · 1789 days since last update

<!-- /section:momentum -->

<!-- section:so-what -->
## The "So What?" (Strategic Takeaway) {#so-what}

Clear Sky Calculator is a business app that is completely free.
It holds a 5/5 rating from 2 reviews.

<!-- speakable-start -->
> **Bottom Line:** Clear Sky Calculator functions as a stable reference utility for sensor validation, but the lack of updates since 2021 confirms it is a legacy support asset. Maintaining the current codebase ensures hardware ecosystem support without requiring further capital allocation.
<!-- speakable-end -->

**Best for:** Researchers, agricultural scientists, and technicians who manage and maintain solar radiation and quantum sensor networks.

<!-- section:pm-actions -->
### PM Action Plan (Next Best Moves)

- [ ] [MAINTAIN] Maintain current codebase because the utility serves as a stable hardware support asset → preserve ecosystem value
<!-- /section:pm-actions -->

<!-- section:outlook -->
### Outlook: Stable

The market for specialized scientific reference tools remains stable, with Clear Sky Calculator providing sufficient value as a static utility. Continued maintenance ensures the tool remains available for researchers, though no further growth is expected without a platform refresh.

- ⚪ The 58-month development freeze indicates the tool has reached functional maturity, serving its purpose as a static hardware support utility.
<!-- /section:outlook -->

<!-- /section:so-what -->

<!-- section:metrics -->
## Key Metrics Summary

| Metric | Value |
| :--- | :--- |
| Overall Rating | 5/5 |
| Total Reviews | 2 |
| Sentiment | Thrilled (90/100) |
| Confidence | Medium |
| Pricing Model | Free |
| Platforms | iOS |
| Key Features | 2 analyzed |
| Trend | Stable |
| Outlook | Stable |
<!-- /section:metrics -->

## Competitor Comparison

| App | Rating | Sentiment | Developer |
| :--- | :--- | :--- | :--- |
| **Clear Sky Calculator** (this app) | 5/5 | Thrilled | Apogee Instruments |
| [Groupon Merchant](https://marlvel.ai/apps/groupon-merchant) | 3.0/5 | n/a | Groupon, Inc. |
| [긱톡 - 재택부업, 프리랜서, 단기알바 정보 플랫폼](https://marlvel.ai/apps/com-gigtalk-gigtalk) | 4.5/5 | N/A | Nextstep Inc. |
| [두란노](https://marlvel.ai/apps/app--971) | N/A/5 | N/A | Duranno |
| [쿠펀치](https://marlvel.ai/apps/coupang-app-coupunch) | 1.0/5 | N/A | Coupang Corp. |
| [아지트 - 함께 소통하는 업무용 커뮤니티](https://marlvel.ai/apps/app--797) | 3.0/5 | N/A | Kakao Corp. |

## Company Profile
- **Developer:** Apogee Instruments
- **Website:** [https://apps.apple.com/us/developer/apogee-instruments/id955609109?uo=4](https://apps.apple.com/us/developer/apogee-instruments/id955609109?uo=4)

## Data Sources & Links
- **App Store:** [View on Apple Store](https://apps.apple.com/us/app/clear-sky-calculator/id974693728?uo=4)
- **Dev Site:** [Official Website](https://apps.apple.com/us/developer/apogee-instruments/id955609109?uo=4)
- **Sources:** Developer website content, App store metadata, User reviews.

## Related Intel Reports
- [*Groupon Merchant*](https://marlvel.ai/apps/groupon-merchant) (Groupon, Inc.) · 3.0/5 Rating
- [*긱톡 - 재택부업, 프리랜서, 단기알바 정보 플랫폼*](https://marlvel.ai/apps/com-gigtalk-gigtalk) (Nextstep Inc.) · 4.5/5 Rating
- [*두란노*](https://marlvel.ai/apps/app--971) (Duranno) · N/A Rating
- [*쿠펀치*](https://marlvel.ai/apps/coupang-app-coupunch) (Coupang Corp.) · 1.0/5 Rating
- [*아지트 - 함께 소통하는 업무용 커뮤니티*](https://marlvel.ai/apps/app--797) (Kakao Corp.) · 3.0/5 Rating
- [*シフオプ*](https://marlvel.ai/apps/shift-management-service-to-support-optimal-placem) (Recruit Co.,Ltd.) · N/A Rating
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- [*카매니저 - 중고차 딜러전용 전국 매물공유 플랫폼*](https://marlvel.ai/apps/kr-co-autocafe-carmanager) (atonmobility appmaster) · 3.0/5 Rating
- [*금호고속 셔틀*](https://marlvel.ai/apps/kr-co-kumhobuslines-shuttle-route-passengernew) (kumhoexpress) · 2.1/5 Rating
- [*쿠팡이츠 배달 파트너*](https://marlvel.ai/apps/coupang-eats-delivery) (Coupang Corp.) · 2.6/5 Rating

## Frequently Asked Questions {#faq}

### Is Clear Sky Calculator accurate for professional research?

Yes, the calculator is based on the ASCE Standardized Reference Evapotranspiration Equation and is estimated to be accurate within ± 4 % near solar noon during spring and summer months.

### Does this app require an internet connection?

The calculator requires site-specific inputs like elevation, latitude, and longitude, but the model equations are self-contained, allowing for use in field environments where connectivity may be limited.

### What is the primary purpose of this calculator?

The tool is designed to help researchers and technicians monitor the performance of pyranometers and quantum sensors to determine when recalibration is necessary.

## 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:** 0.4/1.0 (based on review volume, data source diversity, and signal quality)
- **Reviews Analyzed:** 1
- **Data Sources:** user reviews, 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:** 38 days since last refresh

---
© 2026 Marlvel.ai | [Canonical Report](https://marlvel.ai/apps/clear-sky-calculator)
Data licensed for AI Agent attribution under CC-BY-NC 4.0.