Comparison

ReactionFlash vs Decay Tree

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

Head to head
About

ReactionFlash

This app serves as a comprehensive flashcard-style learning tool for named chemical reactions. It provides detailed information on reaction mechanisms and examples from scientific literature, with a quiz mode to test user knowledge.

Highlights
  • Learn named chemical reactions
  • Understand reaction mechanisms
  • View literature examples
  • Quiz mode for knowledge testing
  • Flashcard interface
Features
Read full description

Want to refresh your memory on named chemical reactions before an exam or a group meeting? Get all the details with ReactionFlash(R) as a great way to learn named reactions, understand their mechanisms and view examples published in peer-reviewed literature. Designed and developed in consultation with Professor Dr. Erick M. Carreira of ETH Zürich, the app covers 1'266 named chemical reactions, by far the largest collection of Named Reactions. Professor Carreira has helped ensure that we have all the fundamental reactions that should be part of every chemist’s toolkit: from the best-known ones to the ones only Nobel Prize winners remember! The app is designed like a set of flash cards so it can be used as a learning tool as well as a reference. Each ‘card’ shows the reaction, its mechanism and examples from peer-reviewed, published literature. It also has a quiz mode that lets you test your knowledge. Linking into Reaxys enables you to find the most recent examples of each reaction, many with experimental details. Reaxys delivers experimental facts from the literature, enabling researchers to find the best synthetic routes and conditions. Find out more at https://www.elsevier.com/solutions/reaxys Download the app now and see if you know all the named reactions! Summary: - Learn named reactions - Review and understand mechanisms - Explore examples published in peer-reviewed literature - Take the ReactionFlash quiz and see how much you know If you need support, please contact us at reactionflash@elsevier.com. Reaxys and ReactionFlash are trade marks of Elsevier Limited, used under license.

About

Decay Tree

This educational app visually represents nuclear decay chains for various nuclides. It graphically displays decay modes and half-lives, alongside detailed tables and graphs of spin, specific activity, and emitted particles.

Highlights
  • Visualizes decay chains
  • Graphical display of decay modes
  • Graphical display of half-lives
  • Tabulated details of spin, specific activity, emitted particles
  • Graphs of spin, specific activity, emitted particles
Features
Read full description

Decay Tree visualizes the whole decay chain for almost any known nuclide. Decay modes and half-lives are graphically shown. In addition, details like spin, specific activity, and emitted particles are tabulated and graphed.

Screenshots

ReactionFlash4 screens
Decay Tree4 screens

Verdict

The call

The clearest difference is rating: ReactionFlash at 4.8 against Decay Tree's 4.1. ReactionFlash also leads on in-app purchases (none vs 2) and ads (none vs shown). Decay Tree's advantage is review sentiment (100% vs 81%) and iOS requirement (12.0 vs 14.0). On price 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

Both are free to download. Decay Tree sells 2 one-off in-app purchases. ReactionFlash asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

ReactionFlash holds the better App Store score, 4.8 against 4.1. That said, the two scores are not equally well evidenced: ReactionFlash has 41 ratings behind it against 7, so its average is the more settled of the two. Written reviews complicate that: 81% of ReactionFlash's written reviews are positive against 100% of Decay Tree's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

ReactionFlash ships an update every 4 months, Decay Tree every 11 months. The most recent releases landed on October 7, 2026 and September 28, 2026 respectively.

Scorecard8 real differences · 2 level
ReactionFlash versus Decay Tree: the parameters behind the verdict, then further details
ParameterReactionFlashDecay Tree
PriceFreeFree
Rating4.8 (41 ratings) — better4.1 (7 ratings)
Positive reviews80.6% of reviews100.0% of reviews — better
Number of ratings41 — better7
Update frequencyEvery 4 months — betterEvery 11 months
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS14.012.0 — better
Further details — not scored
Size37 MB53 MB
Age rating4+4+
DeveloperElsevier LimitedGustaf Holst

Customer experience

ReactionFlash

All ratings41 ratings
Positive95.1%
Neutral2.4%
Negative2.4%
Written reviews31 reviews
Positive80.6%
Neutral6.5%
Negative12.9%

Decay Tree

All ratings7 ratings
Positive85.7%
Neutral0.0%
Negative14.3%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

ReactionFlash

No in-app purchases

2 purchases

Decay Tree

One-time2
  • Radiation Table$0.99
  • Remove Ads$1.99

Questions

Is ReactionFlash free?
ReactionFlash is free to download, with no in-app purchases.
Is Decay Tree free?
Decay Tree is free to download, with in-app purchases available.
Which has better reviews, ReactionFlash or Decay Tree?
ReactionFlash is rated higher. ReactionFlash averages 4.8 out of 5 from 41 ratings, while Decay Tree averages 4.1 from 7 ratings.
Do ReactionFlash or Decay Tree have ads?
Decay Tree shows ads; ReactionFlash does not.
Which is updated more often, ReactionFlash or Decay Tree?
ReactionFlash ships an update every 4 months, and Decay Tree every 11 months. Most recently, ReactionFlash was updated on October 7, 2026 and Decay Tree on September 28, 2026.

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