Start with any of 1 topics: every page lists Hebrew words with their English meanings and part of speech. No sign-up. Hebrew script, with a romanization to sound it out. The rest of each pack is in the app.
Watch Your Language puts Hebrew words like these in a widget on your iPhone Lock Screen and on your Apple Watch face. You see a handful of them every time you check the time, and the app schedules the repeats so the words you keep forgetting come back more often than the ones you already know.
You can add your own words too — from a photo, a page of notes or a spreadsheet.