# Trajectory vs Summe Calculator

The clearest difference is in-app purchases: Trajectory at none against Summe Calculator's 1. Summe Calculator's advantage is ads (none vs shown) and device support (3 vs 1). On price, update cadence and iOS requirement there is nothing between them.

Both are free to download. Summe Calculator sells 1 one-off in-app purchase. Trajectory asks for nothing beyond the download.

Both ship on a similar rhythm, roughly fortnightly. The most recent releases landed on September 8, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Trajectory | Summe Calculator |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Fortnightly | Fortnightly |
| Size | 36 MB | 10 MB |
| Requires iOS | 17.7.2 | **16.0** |
| Devices | iPhone | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Hideaki Uchikoshi](https://appshunter.io/developer/1559575002) | [ESLIP OU](https://appshunter.io/developer/6798785350) |

## What reviewers say

### Trajectory

[App page](https://appshunter.io/ios/app/trajectory-detection/id6511212764)

**Features:** macOS Compatibility

**In-app purchases:** none


### Summe Calculator

[App page](https://appshunter.io/ios/app/summe-calculator/id6798785168)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Summe+ | $5.99 | one-time |


## Frequently asked questions

### Is Trajectory free?

Trajectory is free to download, with no in-app purchases.

### Is Summe Calculator free?

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

### Do Trajectory or Summe Calculator have ads?

Trajectory shows ads; Summe Calculator does not.

### Which is updated more often, Trajectory or Summe Calculator?

Trajectory ships an update fortnightly, and Summe Calculator fortnightly. Most recently, Trajectory was updated on September 8, 2026 and Summe Calculator on September 28, 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.*