Tri vs i
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Tri
This utility app provides the formula and value for calculating triangle properties. It's designed for quick access to mathematical formulas related to triangles.
- Triangle formula display
- Value calculation
- Quick access utility
- Mathematical formulas
Read full descriptionHide full description
App to display a formula and value of a triangle.
i
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.
- Cutting speed calculation
- RPM calculation
- Feed rate calculation
- Hole and shaft tolerance database
- Thread data
- Milling, drilling, and turning operations
Read full descriptionHide full description
iMachinist is a simple to use CNC calculator app that calculates for you the cuttings speed, RPM, feed rate and more for your milling, drilling and turning operations. iMachinist also includes a database for Hole and Shaft Tolerances and different Threads. Threads Data: - Outer Diameter (max/min) - Pitch Diameter (max/min) - Core Diameter (max/min) - Thread Height (max/min) Tolerance Data: - Zone (Shaft/Hole) - Grade (Shaft/Hole) - Diameter (Shaft/Hole) Cutting Calculator: - Tool Diameter - Cutting Speed - Spindle Speed - Number of Teeth - Feed per Tooth - Feed Rate
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Tri | i |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 2.6 (9 ratings) |
| Positive reviews | 100.0% of reviews — better | 33.3% of reviews |
| Number of ratings | 1 | 9 — better |
| Update frequency | Every 12 months — better | Every 13 months |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | Ad-supported | Free — better |
| Devices | iPhone, iPod — better | iPhone |
| Requires iOS | 15.6 — better | 16.0 |
| Further details — not scored | ||
| Size | 4 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | Thirdware.jp | ilan TETRUASHVILI |
Customer experience
Tri
i
In-app purchases
Tri
No in-app purchases
i
No in-app purchases
