Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.
Wikivoyage - the free worldwide travel guide that anyone can edit.
TourPickr - Explore more than 400 000 hidden tourist places in Europe.
Triptipedia - Triptipedia is a free collaborative encyclopedia of travel tips, where everyone can browse, save and share tips for better travel!
TheBesty - Your Personal Travel Assistant in Latin America
The Basetrip - Cities - Travel information for 650+ cities & 230+ countries