# AI Prompt Modifier vs ContextStacker

The clearest difference is in-app purchases: AI Prompt Modifier at none against ContextStacker's 2. AI Prompt Modifier also leads on device support (4 vs 2) and iOS requirement (15.0 vs 17.0). ContextStacker's advantage is update cadence (every 3 days vs monthly). On price and ads there is nothing between them.

Both are free to download. ContextStacker sells 2 in-app purchases, starting at $99.00 per year. AI Prompt Modifier asks for nothing beyond the download.

AI Prompt Modifier ships an update monthly, ContextStacker every 3 days. The most recent releases landed on September 28, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | AI Prompt Modifier | ContextStacker |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 3 days** |
| Size | 4 MB | 7 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Windmillcode LLC](https://appshunter.io/developer/1755065554) | [鹏源 邱](https://appshunter.io/developer/1042192961) |

## What reviewers say

### AI Prompt Modifier

[App page](https://appshunter.io/ios/app/ai-prompt-modifier/id6736705362)

**Features:** Safari Extension

**In-app purchases:** none


### ContextStacker

[App page](https://appshunter.io/ios/app/contextstacker/id6774051551)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Annual | $99.00 | per year |
| Business Annual | $199.00 | per year |


## Frequently asked questions

### Is AI Prompt Modifier free?

AI Prompt Modifier is free to download, with no in-app purchases.

### Is ContextStacker free?

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

### Do AI Prompt Modifier or ContextStacker have ads?

Neither AI Prompt Modifier nor ContextStacker shows ads.

### Which is updated more often, AI Prompt Modifier or ContextStacker?

AI Prompt Modifier ships an update monthly, and ContextStacker every 3 days. Most recently, AI Prompt Modifier was updated on September 28, 2026 and ContextStacker on October 14, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*