# IACUBUS vs Stacks

The clearest difference is in-app purchases: IACUBUS at none against Stacks's 2. IACUBUS also leads on iOS requirement (14.0.0 vs 16.4). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Stacks sells 2 in-app purchases, starting at $9.99 per 3 months. IACUBUS asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | IACUBUS | Stacks |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | Every 3 months |
| Monetization | — | Freemium |
| Size | 22 MB | 77 MB |
| Requires iOS | **14.0.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Jakub Niewelt](https://appshunter.io/developer/1742814360) | [Lewis Hoy](https://appshunter.io/developer/1812196615) |

## What reviewers say

### IACUBUS

[App page](https://appshunter.io/ios/app/iacubus/id6499224968)

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

**In-app purchases:** none


### Stacks

[App page](https://appshunter.io/ios/app/stacks-language-flashcards/id6745429203)

Create flashcards from your own experiences and conversations. This app uses spaced repetition to help you remember vocabulary longer with less study. It supports over 100 languages and offers offline study capabilities.

**Highlights:** Create cards from stories and conversations, Spaced repetition system (FSRS), Offline study mode, Automatic translations, Supports over 100 languages, Romanization for select scripts, Clean, minimal interface

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Stacks+ Quarterly | $9.99 | per 3 months |
| Stacks+ Yearly | $27.99 | per year |


## Frequently asked questions

### Is IACUBUS free?

IACUBUS is free to download, with no in-app purchases.

### Is Stacks free?

Stacks is free to download, with in-app purchases available.

### Do IACUBUS or Stacks have ads?

Neither IACUBUS nor Stacks shows ads.

### Which is updated more often, IACUBUS or Stacks?

IACUBUS ships an update every 3 months, and Stacks every 3 months. Most recently, IACUBUS was updated on October 24, 2026 and Stacks on October 28, 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.*