Shared computers and travel laptops often lack the input method you need. A browser keyboard lets you type, copy, and paste into email or Docs without changing OS settings.
WriteWithin focuses on languages people actually search for — with phonetic maps, Hangul composition, and a learner Romaji→Kana path — plus emoji and practice phrases. Your draft stays in the browser unless you copy it out.
When you need speed practice, open the typing test. When you need accents on a US-only PC, open the language page and type.