# S7 Link vs Ruler & Digital Caliper

The clearest difference is price: Ruler & Digital Caliper at Free against S7 Link's $14.99. Ruler & Digital Caliper also leads on update cadence (every 4 days vs every 4 months) and iOS requirement (17.0 vs 26.0). On ads, in-app purchases and device support there is nothing between them.

Ruler & Digital Caliper is free to download; S7 Link costs $14.99 up front. S7 Link sells 3 one-off in-app purchases and Ruler & Digital Caliper sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

S7 Link ships an update every 4 months, Ruler & Digital Caliper every 4 days. The most recent releases landed on November 10, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | S7 Link | Ruler & Digital Caliper |
| --- | --- | --- |
| Price | $14.99 | **Free** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 4 days** |
| Size | 10 MB | 6 MB |
| Requires iOS | 26.0 | **17.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Carlo Trotti](https://appshunter.io/developer/594070838) | [Yurii Koshkin](https://appshunter.io/developer/1873601061) |

## What reviewers say

### S7 Link

[App page](https://appshunter.io/ios/app/s7-link/id594070835)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Alarms | $2.99 | one-time |
| Charts | $2.99 | one-time |
| OPC Client | $4.99 | one-time |


### Ruler & Digital Caliper

[App page](https://appshunter.io/ios/app/ruler-and-digital-caliper/id6806950163)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime Access | $9.99 | one-time |


## Frequently asked questions

### Is S7 Link free?

S7 Link costs $14.99, and also offers in-app purchases.

### Is Ruler & Digital Caliper free?

Ruler & Digital Caliper is free to download, with in-app purchases available.

### Do S7 Link or Ruler & Digital Caliper have ads?

Neither S7 Link nor Ruler & Digital Caliper shows ads.

### Which is updated more often, S7 Link or Ruler & Digital Caliper?

S7 Link ships an update every 4 months, and Ruler & Digital Caliper every 4 days. Most recently, S7 Link was updated on November 10, 2026 and Ruler & Digital Caliper on November 8, 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.*