NoodleTools has a built-in multilingual proofreader In the Direct Quote, Paraphrase or Summary, and My Ideas fields of a notecard. When the field is blank or there are no errors, you'll see an orange circle with a white checkmark.
When a spelling or grammar error is detected, the circle displays the number of errors found.
Hover your mouse over the marked misspelled word to display a menu with suggestions.
You can also hover your mouse on the orange circle to display more options. Under Settings (the gear icon), you will find options to specify which words to ignore, choose one of 17 different languages, and create a personal user dictionary.