One-Line Legacy Diary is a free one-line-a-day journaling app by indie developer APP4LIFE. Write one line about your day — a feeling, a memory, something you learned — in 60 seconds. Build streaks with milestone badges and daily prompts, and rediscover past years with 'On this day' memories. Browse entries in a calendar, search any word, lock the app with a passcode (everything stays on your device), pick themes and fonts, and export to PDF or text. Free, contains ads, no in-app purchases.