Spell check is based on the web browser. Instructions to turn on spell check for Chrome can be found below:

1) Open Google Chrome and click on Settings button present at the end of the toolbar. Now select Settings menu item.

2) Click on "Show advanced settings..." link given at the bottom of Settings page.

3) Now scroll down a little and click on "Languages and spell-checker settings..." button in "Languages" section.

4) It'll open a new window where you'll see a checkbox "Enable spell checking". Check the option and click on OK button