# Heat Engineer vs onfish angler

The clearest difference is review sentiment: Heat Engineer at 79% against onfish angler's 50%. Heat Engineer also leads on monetization model (free vs free with in-app purchases). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Heat Engineer sells 1 one-off in-app purchase and onfish angler sells 3 in-app purchases, starting at $3.49 per month. Whichever you choose, the download price is not the number that matters.

Heat Engineer ships an update every 2 months, onfish angler every 5 weeks. The most recent releases landed on October 18, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Heat Engineer | onfish angler |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | **78.9% of reviews** | 50.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 306 MB | 90 MB |
| Requires iOS | 16.4 | **15.6** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Heat Engineer Software Ltd](https://appshunter.io/developer/1461678894) | [Stephen Windsor](https://appshunter.io/developer/1568862087) |

## What reviewers say

### Heat Engineer

[App page](https://appshunter.io/ios/app/heat-engineer/id879510552)

This app assists heating engineers and surveyors in collecting property data for heating system installations. It supports heat loss reports for various technologies and includes tools for sound assessments and quick estimations. Data is automatically saved for later review and amendment.

**Highlights:** Heat loss survey for BS EN 12831, CIBSE, and MCS standards, MCS 020 sound assessment for Air Source Heat Pumps, Quick heat loss estimator tool, Automatic data saving and history for amendments, Room-by-room heat loss calculation, Photo capture for rooms and installation locations, Fuel comparisons and running cost calculations

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| MCS 020 PDF Report Token | $2.99 | one-time |


### onfish angler

[App page](https://appshunter.io/ios/app/onfish-angler/id1568915961)

This app helps anglers log observations, save fishing spots, and track patterns to understand the lakes they fish. It organizes data on weather, moon phase, and catches to reveal insights for better fishing.

**Highlights:** Save fishing spots with details, Log observations and catches, Track weather and moon phase, Analyze fish movement patterns, Securely store your data

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OnFish Monthly Subscription | $3.49 | per month |
| Premium Monthly | $3.99 | per month |
| Premium Annual | $34.99 | per year |


## Frequently asked questions

### Is Heat Engineer free?

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

### Is onfish angler free?

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

### Do Heat Engineer or onfish angler have ads?

Neither Heat Engineer nor onfish angler shows ads.

### Which is updated more often, Heat Engineer or onfish angler?

Heat Engineer ships an update every 2 months, and onfish angler every 5 weeks. Most recently, Heat Engineer was updated on October 18, 2026 and onfish angler on October 24, 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.*