# Flow Fill! vs RΔY

The clearest difference is review sentiment: Flow Fill! at 67% against RΔY's 0%. Flow Fill! also leads on rating (4.3 vs 2.0) and in-app purchases (none vs 1). RΔY's advantage is ads (none vs shown) and iOS requirement (12.0 vs 15.0). On price, ratings volume, update cadence and device support there is nothing between them.

Both are free to download. RΔY sells 1 one-off in-app purchase. Flow Fill! asks for nothing beyond the download.

Flow Fill! holds the better App Store score, 4.3 against 2.0. Both are backed by a comparable volume of ratings — 4 and 2 respectively. Written reviews point the same way: 67% of Flow Fill!'s written reviews are positive against 0% of RΔY's.

Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on October 1, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Flow Fill! | RΔY |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.3 (4 ratings)](https://appshunter.io/ios/app/flow-fill/id6755528359/reviews)** | [2.0 (2 ratings)](https://appshunter.io/ios/app/ry/id6758202543/reviews) |
| Number of ratings | **4** | 2 |
| Positive reviews | **66.7% of reviews** | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 310 MB | 163 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Fundora Games](https://appshunter.io/developer/1838341751) | [Raketspel AB](https://appshunter.io/developer/377899145) |

## What reviewers say

### Flow Fill!

[App page](https://appshunter.io/ios/app/flow-fill/id6755528359)

This physics-based puzzle game challenges you to predict how liquid flows through connected tanks. Drag numbered balls to lock in your predictions and watch the simulation unfold. Master the logic to progress through increasingly difficult levels.

**Highlights:** Predictive liquid flow puzzles, Physics-based simulation, Progressive difficulty, Intuitive drag-and-drop controls, Real-time visual feedback, Logic-testing gameplay

**Features:** macOS Compatibility

**In-app purchases:** none


### RΔY

[App page](https://appshunter.io/ios/app/ry/id6758202543)

A tranquil puzzle game that challenges your physics knowledge. Aim a ray to hit all targets in a satisfying and brain-tickling experience.

**Highlights:** Physics-based gameplay, Target hitting puzzles, Tranquil atmosphere, Brain workout, Satisfying challenges

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| No ads | $6.99 | one-time |


## Frequently asked questions

### Is Flow Fill! free?

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

### Is RΔY free?

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

### Which has better reviews, Flow Fill! or RΔY?

Flow Fill! is rated higher. Flow Fill! averages 4.3 out of 5 from 4 ratings, while RΔY averages 2.0 from 2 ratings.

### Do Flow Fill! or RΔY have ads?

Flow Fill! shows ads; RΔY does not.

### Which is updated more often, Flow Fill! or RΔY?

Flow Fill! ships an update every 3 weeks, and RΔY every 3 weeks. Most recently, Flow Fill! was updated on October 1, 2026 and RΔY on September 22, 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.*