Google Cloud Natural Language API - Natural language API using Google machine learning
Grammarly - Clear, effective, mistake-free writing everywhere you type.
monkeylearn - Text Mining Made Easy. Extract and classify information from text. Integrate with your App within minutes.
Synonymful - Improve your vocabulary and communicate like a pro.
spaCy - spaCy is a library for advanced natural language processing in Python and Cython.
TabComplete - Secure Autocomplete for Chrome