# Simple Calendar (Plan Todo) vs Tertiary Planner

The clearest difference is in-app purchases: Tertiary Planner at none against Simple Calendar (Plan Todo)'s 1. Tertiary Planner also leads on ads (none vs shown) and update cadence (every 2 days vs every 6 weeks). Simple Calendar (Plan Todo)'s advantage is iOS requirement (15.6 vs 17.0). On price and device support there is nothing between them.

Both are free to download. Simple Calendar (Plan Todo) sells 1 one-off in-app purchase. Tertiary Planner asks for nothing beyond the download.

Simple Calendar (Plan Todo) ships an update every 6 weeks, Tertiary Planner every 2 days. Both last shipped on October 17, 2026.

## The numbers

| Metric | Simple Calendar (Plan Todo) | Tertiary Planner |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 6 weeks | **Every 2 days** |
| Size | 75 MB | 2 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Huy Huynh](https://appshunter.io/developer/1815003126) | [Alfred Ang](https://appshunter.io/developer/1880940227) |

## What reviewers say

### Simple Calendar (Plan Todo)

[App page](https://appshunter.io/ios/app/simple-calendar-plan-todo/id6746109019)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $5.99 | one-time |


### Tertiary Planner

[App page](https://appshunter.io/ios/app/tertiary-planner/id6785397240)

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

**In-app purchases:** none


## Frequently asked questions

### Is Simple Calendar (Plan Todo) free?

Simple Calendar (Plan Todo) is free to download, with in-app purchases available.

### Is Tertiary Planner free?

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

### Do Simple Calendar (Plan Todo) or Tertiary Planner have ads?

Simple Calendar (Plan Todo) shows ads; Tertiary Planner does not.

### Which is updated more often, Simple Calendar (Plan Todo) or Tertiary Planner?

Simple Calendar (Plan Todo) ships an update every 6 weeks, and Tertiary Planner every 2 days. Most recently, Simple Calendar (Plan Todo) was updated on October 17, 2026 and Tertiary Planner on October 17, 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.*