Numverify - Global phone number validation and lookup API
Bookicious - Find the best new book to read with books collections for makers, founders and entrepreneurs.
Antideo - Email, IP address and phone number validation API service
Goodreads - See what your friends are reading.
RealValidito - Phone Validator | Free Phone Number Validation & Phone Number Lookup Service | Realvalidito
Bookcelerator - A curated directory of books that will make you smarter