3 Seconds Memo vs Calendoc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
3 Seconds Memo
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.
- 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)
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3-Second Memo is a simple notepad app for quickly writing down and saving ideas, notes, and content ideas the moment they come to mind. ■Concept Instead of complex features, 3-Second Memo focuses on letting you write as quickly and easily as possible. It helps you capture ideas you might otherwise think, “I’ll write it down later,” and use the app casually as your personal idea notebook. ■Features of 3-Second Memo - When you launch the app, the memo creation screen opens immediately. - Works offline. Use it anytime, anywhere, whether on the subway or on a plane. - Your memo content is saved only on your own device. It is never used for AI training or similar purposes. - To improve the app, we collect only usage statistics, such as the number of times memos are written. ■Main Features - Start writing immediately after launching the app - View saved memos in chronological order - Organize memos clearly with categories and tags - Convenient offline access - Attach photos to memos to save visual notes, references, and ideas - View attached photos as an album from the category list page - Add a launch widget to the Lock Screen for quick access to memo creation - Local-only data storage. Your data is not saved on the operator’s servers. ■Premium Benefits - Use the app comfortably without ads - Export to Markdown and CSV for easy integration with AI and other tools - Add custom categories, making it possible to manage notes by projects that suit you, such as “Streaming Ideas” or “Development” - Copy memos by category in bulk, so you can easily move each category into other tools ■Important Notice Before using this app, please review the Terms of Use and Privacy Policy below. Japanese - Terms of Use: https://3s-memo.tea-19.com/ja/terms/ - Privacy Policy: https://3s-memo.tea-19.com/ja/privacy/ English - Terms of Use: https://3s-memo.tea-19.com/en/terms/ - Privacy Policy: https://3s-memo.tea-19.com/en/privacy/
Calendoc
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■ Don't merge. Line them up. Work, side gigs, family, fandom. The more calendars you keep, the harder they are to read when everything is mixed into one timeline. You end up chasing colors and working out which event belongs to which role. Switching calendars hides conflicts on the side you cannot see. Calendoc gives each role its own vertical column. The free version lets you compare up to four columns on one screen, keeping work and personal schedules separate while making double-bookings easy to spot. ■ Built for • Using both work and personal calendars • Moving between several schedules for side gigs or multiple jobs • Freelancing with a separate calendar for each client • Keeping concerts, events, and livestreams in a dedicated fan calendar • Wanting work and private life unmixed, but visible at the same time ■ Included for free UP TO FOUR PARALLEL COLUMNS • Show calendars registered on your iPhone, including iCloud, Google, and Exchange, as side-by-side columns • Day and week views with visibility controls for each group • Arrange column order and choose which calendars appear in each group CORE CALENDAR TOOLS • Create, edit, and delete events, including recurring events • Drag to move events or change their duration • Copy and paste, plus Undo • Search across multiple calendars PLAN YOUR DAY • Place Reminders on your timeline as time blocks • See travel time • Home Screen widgets • Dark mode and multiple languages Core calendar features and up to four parallel columns stay free. There are no ads. ■ When you need more A one-time upgrade within this free app unlocks Pro features: five or more columns, Google working locations, RSVP and Google Tasks actions, event templates, and natural-language entry. There is no subscription, and a 14-day free trial is available. ■ Privacy Your event details are not sent to the developer. Connections to external calendar services go directly from your device to the provider. Questions or ideas? Reach out any time through the support page. Calendoc is built by one person, and every message gets read.
Screenshots
Verdict
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.
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. 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.
| Parameter | 3 Seconds Memo | Calendoc |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| Update frequency | Weekly | Weekly |
| Ads | Yes | No — better |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad | iPhone, iPad, Apple Watch — better |
| Requires iOS | 16.4 — better | 18.0 |
| Further details — not scored | ||
| Size | 72 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Aiju Kawase | Toshiki Izumi |
In-app purchases
3 Seconds Memo
- Montly Plan1 Month trial$2.991 Month
- Annual Plan1 Month trial$29.991 Year
Calendoc
- 14-day TrialFree
- Calendoc Pro$19.99









