Comparison

Massive Dev Chart Timer vs KeyLight PRO

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Massive Dev Chart Timer

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
Read full description

The Massive Dev Chart is the world's largest film development chart with easy to use multi step timer and darkroom support for iPhone and iPad. Watch the instructional video at: https://www.youtube.com/watch?v=P915z6THiY8. *** Features *** • Offline copy of The Massive Dev Chart in your pocket • Multi Step Timer with sound notifications • Customizable agitation scheme • Darkroom themes • Dilution Mixer • Support for two-step development and two-step fixing • Support for optional hypoclear and photo flo steps • Automated development time/temperature compensation

About

KeyLight PRO

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
Read full description

Shooting off-camera flash photography is challenging. Optimal exposure settings requires a knowledge of how to balance ISO sensitivity, aperture level, strobe power and strobe proximity to the subject. Because strobe power varies dramatically not only between manufacturers and models but also when external elements such as umbrellas, soft-boxes and lighting gels are used, quickly determining correct exposure settings can be challenging at best, and frustrating at the worst. KeyLight PRO removes all of this guesswork. Easy-to-use calculators quickly and clearly display optimal ISO levels, aperture settings, strobe power levels and strobe-to-subject distances in an intuitive, familiar interface. For the more advanced photographer, the Key Falloff calculator will calculate the proximity of the strobe from the subject in order to meet a desired exposure value falloff over a specific distance. For example, the area behind a subject is 10 feet away, should be 3 stops underexposed relative to the subject, and the strobe is firing at 1/4 power and the camera is at ISO 400. What should the aperture setting be on the camera? With KeyLight PRO, the answer is a tap away. How many strobes does KeyLight PRO support? The Virtual Gear Bag provides an unlimited number of strobe makes, models and settings, and the Strobe Library provides over 100 pre-loaded strobe model configurations. The Gear Bag is readily accessible on all of the calculators, providing quick, easy and accurate exposure settings when swapping between your strobes. Only using one strobe? Keep multiple "set ups" in your Gear Bag under a variety of configurations: bare bulbed, gelled, soft-boxed, umbrellaed, neutral-density filtered, wall-bounced, go-bo'd. There is no limit to the number of ways the light from a single strobe can be modified. Create as many configurations for these light modifiers as you need, and know in an instant how to most effectively utilize them. KeyLight PRO. Control the light.

Screenshots

Massive Dev Chart Timer4 screens
KeyLight PRO4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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.

Scorecard7 real differences · 4 level
Massive Dev Chart Timer versus KeyLight PRO: the parameters behind the verdict, then further details
ParameterMassive Dev Chart TimerKeyLight PRO
Price$9.99$0.99 — better
Rating3.7 (54 ratings)4.0 (4 ratings) — better
Positive reviews70.8% of reviews — better44.4% of reviews
Number of ratings54 — better4
Update frequencyEvery 5 months — betterEvery 26 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank#31 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS12.010.0 — better
Further details — not scored
Size14 MB3 MB
Age rating4+4+
DeveloperFreestyle Photo & ImagingDaniel Brewer

Customer experience

Massive Dev Chart Timer

All ratings54 ratings
Positive63.0%
Neutral7.4%
Negative29.6%
Written reviews216 reviews
Positive70.8%
Neutral8.3%
Negative20.8%

KeyLight PRO

All ratings4 ratings
Positive75.0%
Neutral0.0%
Negative25.0%
Written reviews9 reviews
Positive44.4%
Neutral22.2%
Negative33.3%

Bugs and requests

Massive Dev Chart Timer

Reported bugs

12 issues
  • 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
Show 7 more
  • UI elements overlap on older iPhone models
  • Safelight mode white banner blocks display on iPad
  • Crashes during development process
  • Home screen line emits bright light in darkroom mode
  • App incompatible with newer iOS versions on older devices
  • Notes don't word wrap properly
  • Inconsistent film/developer availability between iPhone and iPad

Requested features

15 requests
  • 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
Show 10 more
  • Volume calculator for stop bath and fixer
  • Background timer functionality
  • Custom step name editing
  • Pull/push development times
  • Stand development support with hour-based timing
  • Apple Watch app
  • Syncing between iPhone and iPad
  • Fahrenheit temperature option
  • Additional common film stocks (Portra, Fuji 400H, Ektar)
  • Ability to add films not in database to custom times

KeyLight PRO

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Massive Dev Chart Timer

No in-app purchases

None

KeyLight PRO

No in-app purchases

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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