# 3 Seconds Memo vs Calendoc

The clearest difference is ads: Calendoc at none against 3 Seconds Memo's shown. 3 Seconds Memo's advantage is iOS requirement (16.4 vs 18.0). On price, update cadence, in-app purchases and device support there is nothing between them.

Both are free to download. 3 Seconds Memo sells 2 in-app purchases, starting at $2.99 per month and Calendoc sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Both ship on a similar rhythm, roughly weekly. The most recent releases landed on October 6, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | 3 Seconds Memo | Calendoc |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | Weekly | Weekly |
| Monetization | Free with in-app purchases | — |
| Size | 72 MB | 18 MB |
| Requires iOS | **16.4** | 18.0 |
| Devices | iPhone, iPad | **iPhone, iPad, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Aiju Kawase](https://appshunter.io/developer/6773546342) | [Toshiki Izumi](https://appshunter.io/developer/1729717097) |

## What reviewers say

### 3 Seconds Memo

[App page](https://appshunter.io/ios/app/3-seconds-memo-simple-notes/id6773546340)

This app allows for rapid note-taking and idea capture, opening directly to a creation screen. It offers offline functionality, local data storage, and organizational tools like categories and tags. Premium features include ad-free usage, data export, and custom categories.

**Highlights:** Immediate memo creation on launch, Offline functionality, Local-only data storage, Organize with categories and tags, Attach photos to memos, Lock Screen widget for quick access, Export to Markdown and CSV (Premium)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Montly Plan | $2.99 | per month |
| Annual Plan | $29.99 | per year |


### Calendoc

[App page](https://appshunter.io/ios/app/calendoc-parallel-calendars/id6791646438)

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 14-day Trial | Free | one-time |
| Calendoc Pro | $19.99 | one-time |


## Frequently asked questions

### Is 3 Seconds Memo free?

3 Seconds Memo is free to download, with in-app purchases available.

### Is Calendoc free?

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

### Do 3 Seconds Memo or Calendoc have ads?

3 Seconds Memo shows ads; Calendoc does not.

### Which is updated more often, 3 Seconds Memo or Calendoc?

3 Seconds Memo ships an update weekly, and Calendoc weekly. Most recently, 3 Seconds Memo was updated on October 6, 2026 and Calendoc on October 16, 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.*