I really hated having to switch languages, when I switched to writing from Hungarian and English. Many times I was writing mail, or working on an article in English, when a Hangouts message popped up where I had all my words underlined by the English spellchecker.
Finally after over a year in progress, guys at Google managed to add the feature to Chrome.
Too bad it's quite hidden at the moment, and even though I followed it on the bug tracker it didn't appear in my basic settings panel.
If you want to enable it, follow the instructions here, or just click here and enable the multi-lingual-spellchecker option.
(NB: Doesn't work on Android, or IOS)
