Comparison

iStackz vs Galileo

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

Head to head
About

iStackz

Features
Read full description

Flashcard organizer, classifying cards in 5 levels from unknown to known. The color of the cards represents a characteristic of the card, typically the duration since the last positive test: the card turns darker over time, indicating the need to refresh it from time to time. This is very useful when e.g. learning Japanese kanji where a large set of characters must be kept in memory. Other color modes provide more detailed means to highlight cards prominently that must be refreshed, or represent the numbers of successes or failures. The app provides tools for testing and learning. Testing is used to assess the proficiency state of the cards, by moving it to the right side (known) or left side (unknown) with the arrow buttons, or by directly dragging the card on the screen. Learning is used to iterate through a short, growing list of cards until the new words are mastered sufficiently for the moment. The next testing session will show if the words stick. Every card has up to four attributes, which can be aligned in specific sequences in the testing and learning tools, to individually train specific skills. In addition to the displayed text, the attributes can be presented in a read aloud form with the text-to-speech function of iOS, with fully customized voices in all supported languages. A growing archive of wordlists is available on the homepage (stackz.com), or new wordlists can be created with the free Stackz List Editor on Windows. Card decks can be downloaded to the Apple Watch, where the card texts can be displayed continuously in the watch face complications for ongoing repetition - tapping on the text in the watch face opens the Stackz watch app to display all attributes of the card.

About

Galileo

Features
Read full description

The goal with Galileo is to explain with simple words, the complex yet beautiful physics that is inside everything in our world. Contents are presented in small articles, written with a simple language. The articles covers various topics from mechanics to nuclear physics. Articles includes images, animations, 3D models and sometimes a little equation. Get a better understanding of physics with Augmented Reality! Place experiments and animated 3D models on you table and explore them by moving around.

Screenshots

iStackz4 screens
Galileo4 screens

Verdict

The call

The clearest difference is in-app purchases: Galileo at none against iStackz's 1. iStackz's advantage is update cadence (every 4 weeks vs every 4 months). On price, ads, device support and iOS requirement there is nothing between them.

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

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. iStackz sells 1 in-app purchase, starting at $1.99 per month. Galileo asks for nothing beyond the download.

UpkeepUpdate frequency

iStackz ships an update every 4 weeks, Galileo every 4 months. The most recent releases landed on October 19, 2026 and October 29, 2026 respectively.

Scorecard2 real differences ยท 4 level
iStackz versus Galileo: the parameters behind the verdict, then further details
ParameteriStackzGalileo
PriceFreeFree
Update frequencyEvery 4 weeks โ€” betterEvery 4 months
AdsNoNo
In-app purchasesYesNo โ€” better
DevicesiPhone, Apple WatchiPhone, iPad
Requires iOS17.617.6
Further details โ€” not scored
Size3 MB65 MB
Age rating4+4+
DeveloperChristoph LuediDavide Fiorino

In-app purchases

1 purchases

iStackz

Subscriptions1
  • Full functionality - monthly$1.991 Month
None

Galileo

No in-app purchases

Questions

Is iStackz free?
iStackz is free to download, with in-app purchases available.
Is Galileo free?
Galileo is free to download, with no in-app purchases.
Do iStackz or Galileo have ads?
Neither iStackz nor Galileo shows ads.
Which is updated more often, iStackz or Galileo?
iStackz ships an update every 4 weeks, and Galileo every 4 months. Most recently, iStackz was updated on October 19, 2026 and Galileo on October 29, 2026.

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