Sensor vs 4DI
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sensor
Access and utilize all your device's sensors with this comprehensive tool. Explore GPS, gyroscope, acceleration, magnetometer, altimeter, and attitude data for various applications and research.
- Access GPS for precise location
- Utilize gyroscope for orientation
- Measure acceleration and movement
- Detect magnetic fields with magnetometer
- Access altimeter and pressure data
- Monitor device attitude (roll, pitch, yaw)
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Unlock the full potential of your iPhone and iPad with Sensor-App, the ultimate tool for accessing and utilizing all of your device's sensors. Whether you're an enthusiast, a developer, or simply curious about your device's capabilities, Sensor-App offers a comprehensive suite of tools at your fingertips. Explore a plethora of sensors including: - **GPS**: Navigate with precision and track your device’s exact location. - **Gyroscope**: Experience precise orientation and rotation insights for enhanced application performance. - **Acceleration Sensor**: Measure the speed and direction of movement, perfect for fitness and motion-based applications. - **Magnetometer**: Detect magnetic field strength and direction, useful for navigation and augmented reality. - **Altimeter/Pressure Sensor**: Access real-time altitude and pressure data, ideal for outdoor adventures. - **Attitude**: Understand device posture with detailed readings of roll, pitch, and yaw. Designed with both power users and beginners in mind, Sensor-App provides intuitive access to your device’s advanced hardware features. Take control of your sensor data and transform how you interact with the world around you. Whether for personal exploration, scientific research, or application development, Sensor-App is your gateway to a more insightful mobile experience.
4DI
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4DI is an offline reference tool for data integrity in regulated environments — built for QA, validation, manufacturing, and laboratory teams working under GxP. The app organizes data integrity knowledge into five areas: ALCOA++ principles, regulatory frameworks, the data lifecycle, typical inspection findings, and a glossary. ALCOA++ PRINCIPLES 10 principles, each with a clear definition and practical examples contrasting good practice with a typical violation: - Attributable - Legible - Contemporaneous - Original - Accurate - Complete - Consistent - Enduring - Available - Traceable (added per the EMA guideline on computerised systems and electronic data in clinical trials, 2023) REGULATORY FRAMEWORKS 7 frameworks side by side, each with a summary, core requirements, and a link to the official source: - FDA 21 CFR Part 11 - EU GMP Annex 11 - MHRA GxP Data Integrity Guidance - EMA Guideline on computerised systems and electronic data in clinical trials (2023) - PIC/S PI 041 - WHO TRS 1033, Annex 4 — Guideline on data integrity (2021) - ICH Q7 Frameworks are tagged by region (US / EU / International). A comparison view highlights key differences across four topics: audit trail, electronic signatures, risk-based approach, and quality culture & human factors. DATA LIFECYCLE Six phases — Creation, Processing, Review & Approval, Reporting, Retention, Archival & Destruction — each mapped to its relevant ALCOA++ principles, typical pitfalls, and regulatory focus. INSPECTION FINDINGS 17 findings modeled on public patterns from FDA Warning Letters, Form 483 observations, and EU GMP non-conformities. Organized by category and severity, each finding lists the principles violated, its regulatory basis, and remediation measures, with links to official databases. Full search included. GLOSSARY 29 terms — ALCOA terms, regulatory abbreviations (CFR, GMP, GLP, GCP...), technical terms (audit trail, metadata, electronic signature), and quality terms (CAPA, deviation, OOS) — each with a definition and context. Bookmark terms for quick access, get a "term of the day," and search even without typing accents. FIVE LANGUAGES 4DI speaks English, German, French, Spanish and Italian. A new installation starts in your iPhone's language when 4DI supports it. You can switch the language any time in the app's Settings. BUILT FOR OFFLINE USE Light, dark, or system appearance. Works entirely offline: no accounts, no tracking, no ads, no permissions required. Bookmarks stay on your device. COMMUNITY & SUPPORT Report a bug, suggest a feature, or flag a content correction through the app's Settings — linked to robspace's public GitHub hub for discussion. For direct support: support@robspace.de. DISCLAIMER: 4DI is a privately developed helping tool. It is not endorsed, certified, or validated by any regulatory authority. Content is for informational purposes only and must not replace official regulatory guidance or professional advice.
Screenshots
Verdict
The clearest difference is ads: 4DI at none against Sensor's shown. 4DI also leads on update cadence (every 5 days vs every 2 months) and iOS requirement (18.6 vs 27.0). Sensor's advantage is device support (3 vs 1). On price and in-app purchases 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Sensor ships an update every 2 months, 4DI every 5 days. The most recent releases landed on October 14, 2026 and October 19, 2026 respectively.
| Parameter | Sensor | 4DI |
|---|---|---|
| Price | Free | Free |
| Rating | 4.0 (4 ratings) — better | — |
| Positive reviews | 55.6% of reviews | — |
| Number of ratings | 4 — better | — |
| Update frequency | Every 2 months | Every 5 days — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, Apple Watch — better | iPhone |
| Requires iOS | 27.0 | 18.6 — better |
| Further details — not scored | ||
| Size | 47 MB | 5 MB |
| Age rating | 4+ | 4+ |
| Developer | Volker Schmitt | Robert Poetzsch |
In-app purchases
Sensor
No in-app purchases
4DI
No in-app purchases









