# Triangle3 vs Haikan Pipit

The clearest difference is price: Haikan Pipit at Free against Triangle3's $3.99. Triangle3's advantage is review sentiment (40% vs 0%) and in-app purchases (none vs 2). On update cadence, device support and iOS requirement there is nothing between them.

Haikan Pipit is free to download; Triangle3 costs $3.99 up front. Haikan Pipit sells 2 in-app purchases, starting at $3.99 per month. Triangle3 asks for nothing beyond the download.

Triangle3 ships an update every 5 weeks, Haikan Pipit every 3 weeks. The most recent releases landed on September 13, 2026 and September 22, 2026 respectively.

## The numbers

| Metric | Triangle3 | Haikan Pipit |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Positive reviews | **40.0% of reviews** | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 weeks | **Every 3 weeks** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 7 MB | 220 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [ryo sasaki](https://appshunter.io/developer/318552526) | [NETSTILL LIMITED LIABILITY CO.](https://appshunter.io/developer/1718197858) |

## What reviewers say

### Triangle3

[App page](https://appshunter.io/ios/app/triangle3/id1643788233)

This app provides advanced calculation tools for field work, specializing in right and unequal triangles. It supports complex shapes like cones, pipes, and screw wings, with AR visualization for floor plans. It also includes standard calculator functions and memory features.

**Highlights:** Right and unequal triangle calculations, Complex shape development (cones, pipes, etc.), Augmented Reality (AR) floor plan visualization, Standard calculator functions with memory, Trigonometric and cosine theorem calculations, PCD and screw wing calculations

**Features:** Vision Pro support

**In-app purchases:** none


### Haikan Pipit

[App page](https://appshunter.io/ios/app/haikan-pipit/id6473008995)

Calculate precise cut lengths for various pipe fittings and view their dimensions in a 3D catalog. Supports multiple fitting types with plans for future additions like sharing and quantity estimation.

**Highlights:** Cut length calculation for fitting combinations, 3D pipe catalog with dimension drawings, Support for DV, TS/HI, HT, White-thread, Water Supply Core, Butt-weld, and Stainless Press-Type fittings, Future updates planned for sharing and quantity estimation, View pipe and fitting shapes and dimensions

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| プロ版（1ヶ月） | $3.99 | per month |
| プロ版（1年間） | $39.99 | per year |


## Frequently asked questions

### Is Triangle3 free?

Triangle3 costs $3.99, with no in-app purchases.

### Is Haikan Pipit free?

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

### Do Triangle3 or Haikan Pipit have ads?

Haikan Pipit shows ads; Triangle3 does not.

### Which is updated more often, Triangle3 or Haikan Pipit?

Triangle3 ships an update every 5 weeks, and Haikan Pipit every 3 weeks. Most recently, Triangle3 was updated on September 13, 2026 and Haikan Pipit on September 22, 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.*