# Codex Calc vs Hierarchical To

The clearest difference is price: Hierarchical To at Free against Codex Calc's $0.99. Hierarchical To also leads on rating (5.0 vs 4.0) and update cadence (every 2 months vs every 6 months). Codex Calc's advantage is in-app purchases (none vs 1) and ads (none vs shown). On review sentiment, ratings volume, device support and iOS requirement there is nothing between them.

Hierarchical To is free to download; Codex Calc costs $0.99 up front. Hierarchical To sells 1 one-off in-app purchase. Codex Calc asks for nothing beyond the download.

Hierarchical To holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

Codex Calc ships an update every 6 months, Hierarchical To every 2 months. The most recent releases landed on June 5, 2026 and June 10, 2026 respectively.

## The numbers

| Metric | Codex Calc | Hierarchical To |
| --- | --- | --- |
| Price | $0.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/codex-calc/id505057155/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hierarchical-to-do-list/id1577074645/reviews)** |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 6 months | **Every 2 months** |
| Monetization | Paid | **Free with in-app purchases** |
| Size | 11 MB | 51 MB |
| Requires iOS | 12.0 | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Driftwood Studio Software LLC](https://appshunter.io/developer/1822849713) | [Yuuki Shimizu](https://appshunter.io/developer/1533588016) |

## What reviewers say

### Codex Calc

[App page](https://appshunter.io/ios/app/codex-calc/id505057155)

This app offers a powerful yet intuitive calculator experience with a variety of modes including scientific, unit conversion, and tip calculation. It features a customizable interface and a detailed history tape for all your calculations.

**Highlights:** Full scientific calculator functions, Unit converter, Tip calculator, RPN mode, History tape, Customizable interface, Multiple visual themes

**Features:** macOS Compatibility

**In-app purchases:** none


### Hierarchical To

[App page](https://appshunter.io/ios/app/hierarchical-to-do-list/id1577074645)

Organize complex projects with infinitely layered tasks. View all parent, child, and grandchild tasks at a glance without multiple taps. Collapse or expand task branches for clarity and utilize repeat functions for recurring to-dos.

**Highlights:** Infinite task layering, Collapse/expand task branches, View all task levels at once, Today's To-do List, Task repeat function, Task move and copy, Completion history

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ads | $2.99 | one-time |


## Frequently asked questions

### Is Codex Calc free?

Codex Calc costs $0.99, with no in-app purchases.

### Is Hierarchical To free?

Hierarchical To is free to download, with in-app purchases available.

### Which has better reviews, Codex Calc or Hierarchical To?

Hierarchical To is rated higher. Codex Calc averages 4.0 out of 5 from 1 ratings, while Hierarchical To averages 5.0 from 1 ratings.

### Do Codex Calc or Hierarchical To have ads?

Hierarchical To shows ads; Codex Calc does not.

### Which is updated more often, Codex Calc or Hierarchical To?

Codex Calc ships an update every 6 months, and Hierarchical To every 2 months. Most recently, Codex Calc was updated on June 5, 2026 and Hierarchical To on June 10, 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.*