# Crassus vs Öltankschau

The clearest difference is iOS requirement: Öltankschau at 9.3 against Crassus's 15.1. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Crassus ships an update every 15 months, Öltankschau every 11 months. The most recent releases landed on October 4, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Crassus | Öltankschau |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 11 months** |
| Monetization | — | Free |
| Size | 76 MB | 31 MB |
| Requires iOS | 15.1 | **9.3** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Crassus GmbH & Co. KG](https://appshunter.io/developer/1475104093) | [ConSoft](https://appshunter.io/developer/397747217) |

## What reviewers say

### Crassus

[App page](https://appshunter.io/ios/app/crassus/id538410244)

**Features:** macOS Compatibility

**In-app purchases:** none


### Öltankschau

[App page](https://appshunter.io/ios/app/oltankschau/id1295099783)

This app provides a quick and objective assessment of heating oil tank systems. It follows current regulations from AwSV and TRwS, specifically TRwS 791-1 and 2. More information is available on the developer's website.

**Highlights:** Objective assessment of heating oil tanks, Follows AwSV and TRwS regulations, Quick system evaluation, Detailed regulatory guidance

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Crassus free?

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

### Is Öltankschau free?

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

### Do Crassus or Öltankschau have ads?

Neither Crassus nor Öltankschau shows ads.

### Which is updated more often, Crassus or Öltankschau?

Crassus ships an update every 15 months, and Öltankschau every 11 months. Most recently, Crassus was updated on October 4, 2026 and Öltankschau on October 3, 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.*