What is Spaced Repetition?

Have you ever finished a book only to forget most of it weeks later? According to research by German psychologist Hermann Ebbinghaus, without review, we forget about 80% of what we learned within a month. However, reviewing at the right intervals can retain memories with minimal effort.

This feature automatically schedules scientifically optimal review times (same day, next day, 1 week later, 1 month later) for records you want to remember, and notifies you when it's time to review.

The Ebbinghaus Forgetting Curve

We forget learned material over time, but not at a constant rate — forgetting is rapid at first, then gradually slows. Reviewing just as you're about to forget is the most efficient way to transfer information to long-term memory.

Review Timing Purpose
1st Same day Initial consolidation. Forgetting is fastest right after learning
2nd Next day Post-sleep review. Sleep organizes memories, making this review highly effective
3rd 1 week later Transition to medium-term memory. Reinforces retention at the optimal forgetting point
4th 1 month later Long-term memory consolidation. After this, memories can last months to years

Main Features

  • Mark Records for Review Double-click the record row you want to remember (long-press on a smartphone) to enter edit mode, then press the " Mark for review" button. A ⏰ icon appears above the date, and 4 review sessions are automatically scheduled. A "Learn more" link next to the button opens this guide page. The tooltip reads "Schedule spaced repetition reminders (next day, 1 week, 1 month) based on the forgetting curve".
  • 3-State Review Icon The ⏰ icon next to the date visually communicates review status at a glance:
    • ⏰ Static: Review scheduled (not yet due)
    • ⏰ Pulsing (graduated): Review needed (due date reached)
      • Same day to 2 days overdue: slightly red, slow pulse
      • 3 to 6 days overdue: red and larger, fast pulse
      • 7+ days overdue: bright red, maximum size, intense pulse
    • ✅ Green check: All 4 reviews completed
  • One-Click Review from Icon Click or tap a pulsing ⏰ icon to instantly mark that review as done. The tooltip shows "Click to mark as reviewed". Icons that are not yet due cannot be clicked.
  • Review Notifications When reviews are due, a banner notification appears at app startup. Simply click "Review now" to open the review panel. Even if you keep the app open, the banner is refreshed automatically when you return to the tab, every hour, and whenever the date changes. The ⏰ icon colors are also redrawn immediately on date change.
  • OS Notifications When the Tab Is Hidden (Opt-in) While you are working in another tab, your browser's OS-level notification can alert you when reviews become due. Enable it from [Settings] → [Goals] tab → "Review notifications (OS)" by clicking "Enable notifications". If you previously blocked the prompt, re-allow it from the lock icon in the address bar. Blocking leaves the other notification channels (banner, ⏰ icon) working as usual.
  • Web Push — Notifications Even When the Browser Is Closed (Opt-in) Enabling the same button also subscribes you to Web Push delivered through Cloudflare Workers, so OS notifications can arrive even after you close the browser entirely. Only the push endpoint URL, public keys, and the next question to display are stored on the server — no full book content or memo history is uploaded (the next question is overwritten when you save the rfnote). You can unsubscribe any time by clicking the button again or revoking permission in your OS notification settings.
  • ❓ Notification Body Shows a "Question" (Testing Effect) The notification body is not just a count — it shows a question auto-generated from the memo of the next due review. Trying to recall the answer just from the notification (retrieval practice) strengthens long-term memory (the Testing Effect). Question rules, in order of priority:
    1. Memos tagged #important / #memorize are prioritized — when several reviews are due the same day, those memos come first. Japanese tags #重要 / #暗記 are also recognized.
    2. Q: ... A: ... format — if you write Q: and A: in the memo, only the Q: part appears in the notification; tap it to reveal the answer in the app.
    3. **bold** or __bold__ — the first bold span is extracted and turned into "… — Do you remember?".
    4. Otherwise — the first non-empty line of the memo (up to 60 characters) is used with the same suffix.
    Example: a memo like Q: What is the break-even point formula? A: Fixed cost ÷ contribution margin #important produces a notification body of just What is the break-even point formula?, and tapping jumps you to the memo for the answer.
  • 👉 Tap a Notification to Jump Straight to the Memo Web Push and OS notifications deep-link directly to the memo whose question was generated. The card is highlighted and the memo is auto-expanded so you can immediately compare it to the answer you recalled. If multiple reviews are due, the review panel opens as a list.
  • ⏰ Notification Time Slots (Morning / Noon / Evening) Pick when notifications arrive in [Settings] → [Goals] tab → "Notification time slots" (multiple selections allowed):
    • Morning (7am): default. Once a day, before commute / class.
    • Noon (12pm): extra reminder during the lunch break.
    • Evening (9pm): ideal before sleep — the brain consolidates memory overnight.
    Filtering uses your local time zone, so notifications follow you when traveling abroad. The same review is never pushed more than once per 24 hours per device (anti-spam guard).
  • Notifications Arrive But No Banner Shows? If Windows "Do Not Disturb" or macOS "Focus" is enabled, notifications are silently routed to the notification center without showing a banner. To see banners:
    • Windows 11: Settings → System → Notifications → turn off "Do Not Disturb", or add Chrome / Edge to "Set priority notifications".
    • macOS: Control Center → turn off Focus, or System Settings → Notifications → enable "Banners" for Chrome / Safari.
    • Per-site (Chrome / Edge): go to chrome://settings/content/notifications and make sure https://www.allisone.co.jp is in the "Allowed" list.
    If the notification appears in the notification center (Windows: Win+N / macOS: click time at top-right), delivery itself is working.
  • ⚠️ "Do Not Disturb" Keeps Turning Back On (Windows 11 pitfall) Windows 11 has "Turn on do not disturb automatically" rules that silently re-enable DND under certain conditions. Even after you toggle it off manually, it comes back within minutes if the rules are active. You must disable the rules themselves for banners to appear reliably.
    1. Open Settings → System → Notifications
    2. Expand "Turn on do not disturb automatically" ()
    3. Uncheck all four:
      • When I'm duplicating my display (external monitor)
      • When I'm playing a game
      • When I'm using an app in full-screen mode (fires during YouTube full-screen or Zoom — the most common culprit)
      • For the first hour after a Windows feature update
    4. Also uncheck "During these times" (scheduled DND)
    5. Finally, toggle "Do not disturb" itself off
    If you use Phone Link, your phone's silent / Do Not Disturb mode may sync to Windows. Check the phone's settings as well.
  • Cross-File Review Notifications Even before opening a file (right after login), a banner shows which files have pending reviews, e.g. "📖 Files with due reviews: BookA, BookB". Review summaries are saved to localStorage each time a file is saved.
  • Review Panel Accessible anytime from [View]→[Review]. The "Due" tab shows items needing review today; the "All" tab shows every review item. The "Due" tab displays a progress bar (4 dots) for each item: completed reviews are green, the current review is orange, and future reviews are gray.
  • Calendar The "Calendar" tab shows a month at a glance. Cells are tinted blue for upcoming reviews, red for overdue ones and green for completed ones; days with pending reviews show a count (●), and days where everything is finished show a check mark. On a wide screen each cell also lists up to two book titles (days with more show the remainder, e.g. "+2"), with completed rounds struck through. On a phone the titles are omitted because the cells are too small, leaving just the count.
    Below the calendar, every review of that month is listed in date order, so you can read which book falls on which day without clicking anything. Today's entries are marked "Today". Click a day to narrow the list to that day, and press [Show whole month] to go back. You can press [Review done] or [Undo] straight from the list. Use ◀ ▶ to move between months and [Today] to come back.
  • Undo Review Completion After marking a review as done, an [Undo] button appears. If you couldn't recall the content, undo it to be reminded again the next day. In the "All" tab, you can also click a completed (green) dot to undo it.
  • Retrieval Practice In the review panel, notes are hidden by default. Try to recall the content first, then click "Show memo" to verify — leveraging scientifically proven retrieval practice.
  • Visual Progress Tracking The "All" tab shows a progress bar for each item, letting you see at a glance how many of the 4 reviews are complete.

How to Use (4 Steps)

  1. Step 1: Mark a Record for Review Double-click the record row you want to remember (long-press on a smartphone) to enter edit mode. Note: a single click (tap) does not open edit mode. In edit mode, a " Mark for review" button appears below the record.
    A record in edit mode. Below the note are Delete, Mark for review, Learn more, Cancel and OK buttons, with Mark for review outlined in red
    Figure 1 — Double-clicking the record row (long-press on a smartphone) opens edit mode and reveals the [Mark for review] button (tap/click to enlarge)

    On a smartphone or tablet (narrow screens), long-pressing opens the full-screen "Edit record" panel. The " Mark for review" button sits below the notes field, on the row just above [Delete] [Cancel] [OK]. Pressing it closes the panel and shows the ⏰ above the date, exactly as on a computer. Note: this row appears in version 20260903c and later. Earlier versions show only [Delete] [Cancel] [OK] in that panel.

    The full-screen Edit record panel on a smartphone. Below the notes field, the [Mark for review] button (with a brain icon) is outlined in red, with [Delete] [Cancel] [OK] on the row beneath it
    Figure 1b — On a smartphone the full-screen "Edit record" panel opens. [Mark for review] sits on the row just above [Delete] [Cancel] [OK] (tap/click to enlarge)
    Pressing it closes edit mode and shows a ⏰ icon above the date — that is the confirmation.
    A record marked for review. A clock icon, outlined in red, appears above the date
    Figure 2 — Once set, a ⏰ appears above the date. Pressing that ⏰ marks that round as reviewed (tap/click to enlarge)
  2. Step 2: Wait for Review Timing The review schedule (same day, next day, 1 week, 1 month) is set automatically. When a review is due, the ⏰ icon pulses with graduated urgency. The more overdue, the faster, larger, and redder the pulse becomes.
  3. Step 3: Review There are two ways to review: (A) Click the pulsing ⏰ icon to directly mark that review as done. (B) Open the review panel via the startup banner or [View]→[Review], try to recall the content before clicking "Show memo" to check.
  4. Step 4: Click "Review Done" (or Undo) After reviewing in the panel, click the "Review done" button. If you couldn't recall the content, click [Undo] to be reminded again the next day. A celebration message appears when all 4 reviews are complete.

Recommended Use Cases

Exam preparation:
Mark key formulas and concepts from textbooks for review. Instead of last-minute cramming, build lasting knowledge systematically.

Business book insights:
Mark actionable ideas and frameworks you want to apply at work. Repeated recall helps translate knowledge into action.

Language learning and technical reading:
Mark new vocabulary and concepts for efficient vocabulary building and knowledge construction.

Book club preparation:
Mark memorable passages so you can articulate your thoughts clearly at the next meeting.

Tips for Maximum Effectiveness

  • Be selective Only mark truly important content. Too many items increase review burden and reduce sustainability.
  • Write notes in your own words Research shows that summarizing in your own words (elaboration) produces stronger memory traces than copying text verbatim.
  • Always try to recall first Before viewing your notes, attempt to recall the content. This "effortful retrieval" is the most powerful memory strengthening technique.
  • Review before bed Sleep consolidates memories, making bedtime review especially effective. The review panel is always accessible from the View menu, perfect for a nightly routine.
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