How Boostabulary works

Turn any English material into Cambridge-style practice, then keep the words from slipping away.

Put it on your phone

Boostabulary works as an app on your phone.

No app store, no download — your browser puts an icon on your home screen and it opens full-screen, without the address bar.

iPhone & iPad
  1. Open the site in Safari and tap the Share button — at the bottom of the screen on iPhone, at the top on iPad.
  2. Scroll down and tap Add to Home Screen
  3. Tap Add in the top right.

Safari is the surest route. Chrome and other browsers on iPhone can do this too on recent versions of iOS, but the wording of the menu differs — if you cannot find it, switch to Safari.

Android
  1. In Chrome, tap the three dots in the top right.
  2. Tap Install app, or Add to Home screen if you do not see it.
  3. Confirm with Install.

Chrome sometimes offers this by itself in a bar at the bottom — that works too.

You stay signed in, so the app opens straight on the create screen. To remove it, press and hold the icon and delete it like any other app.

Making material

1
Give it something to work from Paste a text, type your own list of words, or photograph a coursebook page. With a photo, words you have underlined or highlighted are detected and prioritised where possible — though detection is not perfect, so check the list and add anything missed through the word-list tab.
2
Choose the level and how much B1 to C2, and either 8 or 12 words. Level guides both which words get picked and how demanding the exercises are.
3
Pick what to generate The full set, or vocabulary only. Vocabulary only is faster and cheaper, and you can still add the exercises afterwards without spending another generation.

What you get

ExerciseModelled onWhat it practises
Vocabulary list Definition, part of speech, example sentence and CEFR level for each item
Multiple choice Reading & Use of English, Part 1 Choosing between near-synonyms; every wrong option is explained, not just the right one
Word formation Reading & Use of English, Part 3 Building the right derived form — prefixes, suffixes, change of word class
Matching Word to meaning, in rounds. Built instantly and available in every mode

Everything is generated fresh each time, so the same text will not give you the same worksheet twice.

The vocabulary bank

Generating a worksheet solves today's lesson. The bank solves the harder problem: words met once and never seen again are words lost. After each generation you tick the items worth keeping, and they go into your bank.

From then on the bank decides when to show each word back to you, using a method called the Leitner system.

The bank stays open even when your generation limit is used up or your subscription has lapsed. Words you have already collected remain yours.

The five boxes

Picture five boxes on a shelf. Every new word starts in box 1. Each box has its own waiting time before that word comes back to you:

1
1 day
2
3 days
3
7 days
4
14 days
5
30 days
← just learned solid →

How a word moves

A word that reaches box 5 counts as mastered. Getting there takes 4 correct recalls spread over about 4 weeks — which is the point: remembering something four times across a month is very different from recognising it four times in one afternoon. After box 5 the word comes back every 30 days, so mastered does not mean forgotten about.

Why send a forgotten word all the way back? Forgetting is evidence that the gap was already too long for that word. Moving it down one step would repeat a gap you have just proved to be too wide. Starting over is the honest response — and words rarely stay in box 1 for long the second time.

Why spacing beats repetition

Reviewing a word five times in one sitting feels productive and does almost nothing: each repetition is easy because the answer is still fresh, and easy recall builds little. Spacing forces you to retrieve the word when it has begun to fade — the effort of that retrieval is what strengthens the memory. The growing intervals are deliberately set just short of the point where you would lose the word entirely.

This is the same principle behind Anki and similar tools, kept to five fixed boxes rather than an adaptive algorithm — simpler to follow, and easy to explain to a class.

Reviewing

Open the bank and you will see how many words are due. In a review you are shown a definition and asked to recall the word — the harder direction, and the one that builds active vocabulary rather than passive recognition. Turn the card over for the word and an example sentence, then say honestly whether you knew it.

Be strict with yourself. "I sort of knew it" is a no — the system only works if the boxes reflect what you can actually retrieve.

Reading the progress bars

The bars on the bank page show how many words sit in each box. Early on everything piles up on the left; over weeks the mass drifts right. A word dropping back to box 1 is not a failure — it is the system catching something before it was lost for good.

Saving the same word twice does not reset it. If you generate material that happens to include a word already in your bank, its definition and example are refreshed but its box and schedule stay exactly where they were.

Generations and limits

One generation is one run of the material maker, whichever input you use. The trial gives you 7 over 3 days; a subscription gives you 50 in each 30-day period, counted from the day you paid rather than from the first of the month.

Start the free trial