# Spark7 vs Stack Flow

The clearest difference is in-app purchases: Stack Flow at none against Spark7's 5. Stack Flow also leads on update cadence (daily vs every 5 days) and iOS requirement (15.0 vs 17.0). Spark7's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. Spark7 sells 5 one-off in-app purchases. Stack Flow asks for nothing beyond the download.

Spark7 ships an update every 5 days, Stack Flow daily. The most recent releases landed on October 17, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Spark7 | Stack Flow |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (45 ratings)](https://appshunter.io/ios/app/spark7-chain-reaction-game/id6759691707/reviews)** | — |
| Number of ratings | **45** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 5 days | **Daily** |
| Monetization | Free with in-app purchases | — |
| Size | 133 MB | 129 MB |
| Requires iOS | 17.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Andrew Cohen](https://appshunter.io/developer/1880237804) | [Dipayon Debnath Dip](https://appshunter.io/developer/1566993708) |

## What reviewers say

### Spark7

[App page](https://appshunter.io/ios/app/spark7-chain-reaction-game/id6759691707)

This electric number puzzle game challenges your brain with dropping numbered balls and creating explosive chain reactions. It's designed by a brain scientist to improve cognitive skills like spatial reasoning and problem-solving.

**Highlights:** Numbered ball dropping gameplay, Explosive chain reaction combos, Global leaderboards and replays, Cognitive skill enhancement, Satisfying and engaging puzzles, Drop7 alternative

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Replay | $0.99 | one-time |
| 3 Replays | $1.99 | one-time |
| Remove Ads | $2.99 | one-time |
| 10 Replays | $3.99 | one-time |
| 50 Replays | $9.99 | one-time |


### Stack Flow

[App page](https://appshunter.io/ios/app/stack-flow-soap-cutting/id6793167382)

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

**In-app purchases:** none


## Frequently asked questions

### Is Spark7 free?

Spark7 is free to download, with in-app purchases available.

### Is Stack Flow free?

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

### Do Spark7 or Stack Flow have ads?

Stack Flow shows ads; Spark7 does not.

### Which is updated more often, Spark7 or Stack Flow?

Spark7 ships an update every 5 days, and Stack Flow daily. Most recently, Spark7 was updated on October 17, 2026 and Stack Flow on September 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.*