# Tri vs i

The clearest difference is review sentiment: Tri at 100% against i's 33%. Tri also leads on rating (5.0 vs 2.6). i's advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, update cadence, in-app purchases and device support there is nothing between them.

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

Tri holds the better App Store score, 5.0 against 2.6. That said, the two scores are not equally well evidenced: i has 9 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Tri's written reviews are positive against 33% of i's.

Tri ships an update every 12 months, i every 13 months. The most recent releases landed on October 20, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Tri | i |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/tri-func/id496807268/reviews)** | [2.6 (9 ratings)](https://appshunter.io/ios/app/i-machinist/id1456473668/reviews) |
| Number of ratings | 1 | **9** |
| Positive reviews | **100.0% of reviews** | 33.3% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 12 months** | Every 13 months |
| Monetization | Ad-supported | **Free** |
| Size | 4 MB | 8 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Thirdware.jp](https://appshunter.io/developer/464228680) | [ilan TETRUASHVILI](https://appshunter.io/developer/940821251) |

## What reviewers say

### Tri

[App page](https://appshunter.io/ios/app/tri-func/id496807268)

This utility app provides the formula and value for calculating triangle properties. It's designed for quick access to mathematical formulas related to triangles.

**Highlights:** Triangle formula display, Value calculation, Quick access utility, Mathematical formulas

**Features:** Vision Pro support

**In-app purchases:** none


### i

[App page](https://appshunter.io/ios/app/i-machinist/id1456473668)

This utility app assists machinists with CNC calculations, including cutting speed, RPM, and feed rate. It also provides databases for hole and shaft tolerances, as well as detailed thread specifications.

**Highlights:** Cutting speed calculation, RPM calculation, Feed rate calculation, Hole and shaft tolerance database, Thread data, Milling, drilling, and turning operations

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

**In-app purchases:** none


## Frequently asked questions

### Is Tri free?

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

### Is i free?

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

### Which has better reviews, Tri or i?

Tri is rated higher. Tri averages 5.0 out of 5 from 1 ratings, while i averages 2.6 from 9 ratings.

### Do Tri or i have ads?

Tri shows ads; i does not.

### Which is updated more often, Tri or i?

Tri ships an update every 12 months, and i every 13 months. Most recently, Tri was updated on October 20, 2026 and i 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.*