# Compound Calculator vs Second Eye

The clearest difference is update cadence: Compound Calculator at every 5 days against Second Eye's fortnightly. Second Eye's advantage is iOS requirement (15.1 vs 17.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Compound Calculator sells 3 in-app purchases, starting at $2.99 per month and Second Eye sells 2 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

Compound Calculator ships an update every 5 days, Second Eye fortnightly. The most recent releases landed on August 19, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | Compound Calculator | Second Eye |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 days** | Fortnightly |
| Size | 5 MB | 34 MB |
| Requires iOS | 17.6 | **15.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 9+ |
| Developer | [乐祥 胡](https://appshunter.io/developer/1572365721) | [PRAGMATIC TECH INNOVATIONS LTD](https://appshunter.io/developer/1575147856) |

## What reviewers say

### Compound Calculator

[App page](https://appshunter.io/ios/app/compound-calculator-lite/id6749442265)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Compound Calculator - Pro 30days | $2.99 | per month |
| Compound Calculator - Pro 360days | $14.99 | per year |
| Compound Calculator Pro - lifetime | $19.99 | one-time |


### Second Eye

[App page](https://appshunter.io/ios/app/second-eye/id6760843474)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Monthly | $3.99 | per month |
| Expand Pack | $1.99 | one-time |


## Frequently asked questions

### Is Compound Calculator free?

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

### Is Second Eye free?

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

### Do Compound Calculator or Second Eye have ads?

Neither Compound Calculator nor Second Eye shows ads.

### Which is updated more often, Compound Calculator or Second Eye?

Compound Calculator ships an update every 5 days, and Second Eye fortnightly. Most recently, Compound Calculator was updated on August 19, 2026 and Second Eye on September 10, 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.*