# PRISM Instrument vs SparkCalc

The clearest difference is update cadence: SparkCalc at every 4 weeks against PRISM Instrument's every 51 months. PRISM Instrument's advantage is iOS requirement (13.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. PRISM Instrument sells 1 in-app purchase, starting at $29.49 per year and SparkCalc sells 2 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

PRISM Instrument ships an update every 51 months, SparkCalc every 4 weeks. The most recent releases landed on October 29, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | PRISM Instrument | SparkCalc |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 51 months | **Every 4 weeks** |
| Size | 30 MB | 3 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Prismium GmbH](https://appshunter.io/developer/1416443576) | [文君 李](https://appshunter.io/developer/1801128255) |

## What reviewers say

### 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 |


### SparkCalc

[App page](https://appshunter.io/ios/app/sparkcalc/id6743084972)

**Features:** Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly Premium Membership | $2.99 | per month |
| Annual Premium Membership | $8.99 | per year |


## Frequently asked questions

### Is PRISM Instrument free?

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

### Is SparkCalc free?

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

### Do PRISM Instrument or SparkCalc have ads?

Neither PRISM Instrument nor SparkCalc shows ads.

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

PRISM Instrument ships an update every 51 months, and SparkCalc every 4 weeks. Most recently, PRISM Instrument was updated on October 29, 2026 and SparkCalc on October 25, 2026.

---

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