Anki is the gold standard for retention — the FSRS scheduling it popularized is the same engine behind Capecho's review. Its one tax is building every card by hand, and that's the exact friction Capecho removes: one keystroke runs on-device OCR to grab the word and its sentence off whatever you're reading — an article, a PDF, a video, your IDE — or copy-paste, no card-building. I leaned on Anki over the closed alternatives because FSRS is open and your words always export straight back to it.