Everything FlexLex does.

Shared across every mode

A word picker so a session can be aimed at exactly the words you want. Status filters for new, hard, don’t know, know and starred. Direction control — term to translation or the reverse. Star any word to build a manual focus list. Images on cards. And text-to-speech in the set’s own language on every card.

Synonym-aware checking: a card reading big; large; huge accepts any of the three, so you’re not marked wrong for knowing a different correct answer.

Scan a printed page

Photograph a textbook page, a printed word list or a worksheet and FlexLex pulls the vocabulary out. Recognition runs on the device with Google ML Kit — no upload, and it works with no signal.

Table reconstruction, not text soup

Raw OCR hands back a jumble of lines. FlexLex reads the bounding boxes: it looks for two distinct horizontal clusters — a term column and a translation column — splits on the largest gap, and pairs entries by nearest vertical position. A two-column vocabulary table comes back as real term/translation pairs. If there’s no column layout to find, it falls back to row grouping instead of guessing.

Handwriting OCR — two engines, merged

Your own handwritten notes work too. On Android, FlexLex preprocesses the image on a background thread and then runs PaddleOCR and Google ML Kit in parallel, merging the two results — because handwriting is exactly the case where any single engine is unreliable. On iOS it bridges to Apple’s Vision recogniser. Models are loaded once and kept warm.

Multi-page merging & an editable review

Shoot several pages in a row and they merge into one import. Nothing is added blind: every extracted pair lands in an editable review list first, where you fix, split, swap sides or delete rows before they become a set.

Import a spreadsheet

Drop in .xlsx (Excel), .csv, .tsv or .json and it becomes a set, with column mapping handled for you and no row limit in the app.

Build a set in your browser

flexlex.app/create builds or imports a set on the web, lets you study it right there in the browser, and sends it to your phone as a single link or a QR code. No account, and nothing is uploaded.

Save words as you browse

Words picked up elsewhere on the phone land in a Saved from web shelf, with the language detected on-device, ready to be filed into the right set later. And when you do type a card by hand, FlexLex offers an on-device translation suggestion for the other side.

What each word carries

An ease factor (starts at 2.50, floored at 1.30), an interval in days, and a repetition count — plus its own lifetime accuracy. Every answer you give, in any of the nine modes, maps to an SM-2 quality score and updates that word’s state.

How the interval grows

First success: +1 day. Second: +6 days. After that the interval is multiplied by that word’s ease factor every time — days become weeks, weeks become months. Miss it and repetitions reset to zero and the word comes straight back.

The ease factor itself is adjusted after every answer, so a word you keep fumbling stays permanently more frequent than one you own.

The Review queue & knowledge status

A due-today queue across every set, so you open the app and it decides what to show you. Each word also gets a derived knowledge status — new, don’t know, hard, know — computed from its repetitions and ease, which drives the filters and the per-set “learned” percentage.

On-device translation, 50+ languages

Google ML Kit translation models (Apple’s Translation framework on iOS 17.4+), downloaded per language from a manager screen in Settings and then fully offline. This is what powers tap-to-translate in Story mode and the suggestions when you type a card by hand.

Offline spell check with real Hunspell dictionaries

Not the keyboard’s spell checker. FlexLex downloads genuine Hunspell dictionary and affix files, applies the affix rules to expand every base form into all of its inflections, and stores the result locally — the Czech expansion alone runs to roughly 4 million word forms.

Lookups run in a dedicated long-lived background isolate, so a multi-million-word dictionary never makes the keyboard stutter, and a load guard skips any dictionary too heavy for a given device rather than starving the app. Around 23 languages are covered.

Pronunciation in ~27 languages

Tap to hear a word in the set’s own language. FlexLex checks the device actually has voice data for that language first, instead of silently reading a German word with an English voice and teaching you the wrong sound.

Article colour-coding for gendered languages

German der / die / das and its equivalents get colour-coded, and the article can be stripped for sorting so your set alphabetises on the noun. Gender becomes something you see rather than a second thing to memorise. The rules are yours to edit.

Any language pair, including the ones nobody covers

You write both sides of every card, so FlexLex works for English–Japanese, Spanish–French, Latin, medical terminology or your chemistry vocabulary. There is no course catalogue to be missing from.

No account. No cloud. No copy of your words anywhere.

Sets, folders, words, progress and settings live in a single local SQLite database on the device. There is no sign-up, no sync and no server-side copy — not as a setting you can turn off, but as an architecture with nowhere to send it.

Backup and one-tap restore

Export every set, folder, image and scrap of progress into a single .flexlex.backup file, and restore it in one tap. Tap that file in a chat app or file manager and it opens straight into the restore flow.

Backups you didn’t have to remember

The first time you open FlexLex after an update that changes the database, it silently writes a full backup to your public Downloads folder. That file survives uninstalling the app entirely. Underneath, the app also snapshots the database before any migration runs and keeps the last two — and migrations are additive-only by policy, with every schema version regression-tested, so an update can’t quietly eat your data.

Share a set — with no server involved

A shared set is a link like flexlex.app/s#… where the entire set travels inside the URL fragment — the part of a URL a browser never sends to a server. There’s no upload, no set ID, no database row and nothing that could be logged or leaked. It opens in the app if you have it, and in a browser if you don’t. QR codes too, for the person sitting next to you.

Deleting means deleting

“Delete all data” is an explicit type-to-confirm action in Settings and the only wipe path in the app. Device-transfer restore is deliberately disabled so a fresh install can’t have stale data pushed over it.