# Massive Dev Chart Timer vs KeyLight PRO

The clearest difference is price: KeyLight PRO at $0.99 against Massive Dev Chart Timer's $9.99. KeyLight PRO also leads on rating (4.0 vs 3.7) and iOS requirement (10.0 vs 12.0). Massive Dev Chart Timer's advantage is review sentiment (71% vs 44%) and update cadence (every 5 months vs every 26 months). On ads, in-app purchases, monetization model and device support there is nothing between them.

Massive Dev Chart Timer costs $9.99 and KeyLight PRO $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

KeyLight PRO holds the better App Store score, 4.0 against 3.7. That said, the two scores are not equally well evidenced: Massive Dev Chart Timer has 54 ratings behind it against 4, so its average is the more settled of the two. Written reviews complicate that: 71% of Massive Dev Chart Timer's written reviews are positive against 44% of KeyLight PRO's, so the app with the better star average is not the one people write more warmly about.

Massive Dev Chart Timer ships an update every 5 months, KeyLight PRO every 26 months. The most recent releases landed on September 28, 2026 and September 23, 2026 respectively.

## The numbers

| Metric | Massive Dev Chart Timer | KeyLight PRO |
| --- | --- | --- |
| Price | $9.99 | **$0.99** |
| Rating | [3.7 (54 ratings)](https://appshunter.io/ios/app/massive-dev-chart-timer/id402405770/reviews) | **[4.0 (4 ratings)](https://appshunter.io/ios/app/keylight-pro/id635455188/reviews)** |
| Number of ratings | **54** | 4 |
| Positive reviews | **70.8% of reviews** | 44.4% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 26 months |
| Monetization | Paid | Paid |
| Best chart rank | **#32** | — |
| Size | 14 MB | 3 MB |
| Requires iOS | 12.0 | **10.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Freestyle Photo & Imaging](https://appshunter.io/developer/1786429988) | [Daniel Brewer](https://appshunter.io/developer/635455211) |

## What reviewers say

### Massive Dev Chart Timer

[App page](https://appshunter.io/ios/app/massive-dev-chart-timer/id402405770)

**Currently charting:** #32 Top Paid · Photo & Video (US App Store)

This app provides an offline film development chart and a multi-step timer for photographers. It includes customizable agitation, darkroom themes, and support for various developing and fixing steps. It also offers automated compensation for development time and temperature.

**Highlights:** Offline film development chart, Multi-step timer with sound notifications, Customizable agitation schemes, Darkroom themes, Dilution mixer, Automated time/temperature compensation

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 📚 Comprehensive film and developer database
- ⏱️ Reliable timer with agitation reminders
- 🎯 Easy-to-use interface for darkroom work
- 🌙 Darkroom mode with red/black display
- ✏️ Customizable development times and profiles

**What reviewers complain about**

- 🚫 Black and white film only (no color film support)
- 🐛 Recent update broke HC110 dilution display
- 🐛 App crashes on certain devices/iOS versions
- 💰 Price point ($8.99-$11.99) for limited functionality
- 🔍 Poor search functionality for films

**Reported bugs**

- HC110 dilution section displays only letters, not ratios
- Dilution ratios not calculating when solution amount adjusted
- App crashes after selecting film speed
- Crashes on iPad with new update
- Timer display shows three dots instead of seconds

**Requested features**

- Color film support (C-41, E-6, ECN-2 processes)
- Search functionality by film brand/name
- Ability to add custom process steps (presoak, toning)
- Individual agitation control per development stage
- Continuous agitation option


### KeyLight PRO

[App page](https://appshunter.io/ios/app/keylight-pro/id635455188)

This app simplifies off-camera flash photography by providing calculators for optimal exposure settings. It helps photographers determine ISO, aperture, strobe power, and distance, removing guesswork for both beginners and advanced users. Manage multiple lighting setups and modifiers with its virtual gear bag.

**Highlights:** Exposure calculators (ISO, aperture, strobe power, distance), Key Falloff calculator, Virtual Gear Bag for unlimited strobe configurations, Strobe Library with 100+ pre-loaded models, Support for various light modifiers, Save multiple setups

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Massive Dev Chart Timer free?

Massive Dev Chart Timer costs $9.99, with no in-app purchases.

### Is KeyLight PRO free?

KeyLight PRO costs $0.99, with no in-app purchases.

### Which has better reviews, Massive Dev Chart Timer or KeyLight PRO?

KeyLight PRO is rated higher. Massive Dev Chart Timer averages 3.7 out of 5 from 54 ratings, while KeyLight PRO averages 4.0 from 4 ratings.

### Do Massive Dev Chart Timer or KeyLight PRO have ads?

Neither Massive Dev Chart Timer nor KeyLight PRO shows ads.

### Which is updated more often, Massive Dev Chart Timer or KeyLight PRO?

Massive Dev Chart Timer ships an update every 5 months, and KeyLight PRO every 26 months. Most recently, Massive Dev Chart Timer was updated on September 28, 2026 and KeyLight PRO on September 23, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*