# HEV vs PRISM Instrument

The clearest difference is update cadence: HEV at every 5 weeks against PRISM Instrument's every 51 months. PRISM Instrument's advantage is device support (3 vs 1) and iOS requirement (13.0 vs 15.0). On price, ads and in-app purchases there is nothing between them.

Both are free to download. HEV sells 3 one-off in-app purchases and PRISM Instrument sells 1 in-app purchase, starting at $29.49 per year. Whichever you choose, the download price is not the number that matters.

HEV ships an update every 5 weeks, PRISM Instrument every 51 months. The most recent releases landed on October 26, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | HEV | PRISM Instrument |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 5 weeks** | Every 51 months |
| Size | 8 MB | 30 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [eXtenso IT-Services AG](https://appshunter.io/developer/923389706) | [Prismium GmbH](https://appshunter.io/developer/1416443576) |

## What reviewers say

### HEV

[App page](https://appshunter.io/ios/app/hev-protokoll/id1079922217)

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Wohnungsprotokoll kaufen | $17.99 | one-time |
| 5 Protocols | $69.99 | one-time |
| 10 Protocols | $99.99 | one-time |


### PRISM Instrument

[App page](https://appshunter.io/ios/app/prism-instrument/id1552249113)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PRISM Instrument App | $29.49 | per year |


## Frequently asked questions

### Is HEV free?

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

### Is PRISM Instrument free?

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

### Do HEV or PRISM Instrument have ads?

Neither HEV nor PRISM Instrument shows ads.

### Which is updated more often, HEV or PRISM Instrument?

HEV ships an update every 5 weeks, and PRISM Instrument every 51 months. Most recently, HEV was updated on October 26, 2026 and PRISM Instrument on October 29, 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.*