# i vs CalcEngineer

The clearest difference is update cadence: CalcEngineer at every 2 days against i's every 6 months. i's advantage is iOS requirement (11.0 vs 17). On price, rating, ratings volume and ads there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for i against 5.0 for CalcEngineer. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

i ships an update every 6 months, CalcEngineer every 2 days. The most recent releases landed on October 7, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | i | CalcEngineer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/i-droponics/id1551871602/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/calcengineer/id6748969344/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 2 days** |
| Monetization | Free | Free |
| Size | 90 MB | 10 MB |
| Requires iOS | **11.0** | 17 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 9+ |
| Developer | [Linnkr Inc.](https://appshunter.io/developer/1551871604) | [Justin Bush](https://appshunter.io/developer/1828308327) |

## What reviewers say

### i

[App page](https://appshunter.io/ios/app/i-droponics/id1551871602)

This app guides users through routine operations for a specific hydroponic system. It offers growing guides, scheduling, fertilization advice, record-keeping, and troubleshooting to support daily, weekly, and periodic tasks. It's designed for owners of the TAPKIT system.

**Highlights:** Growing guides, Scheduling and notifications, Fertilization advice, Record keeping and analysis, Troubleshooting system, Instructional videos, Real-time sensor alerts

**Features:** macOS Compatibility

**In-app purchases:** none


### CalcEngineer

[App page](https://appshunter.io/ios/app/calcengineer/id6748969344)

This app provides professional engineering calculations for compressed air systems. It helps engineers and technicians determine CFM requirements, size compressors and tanks, and analyze pressure drops for optimized pneumatic systems.

**Highlights:** CFM Calculator, Compressor & Tank Sizing, Pressure Drop Analysis, Flow Velocity & Pipe Sizing, Multiple CFM Entries, General Engineering Calculator Suite

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is i free?

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

### Is CalcEngineer free?

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

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

i and CalcEngineer are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.

### Do i or CalcEngineer have ads?

Neither i nor CalcEngineer shows ads.

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

i ships an update every 6 months, and CalcEngineer every 2 days. Most recently, i was updated on October 7, 2026 and CalcEngineer on October 1, 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.*