Apps with 'Topic tags' feature

Qiqqa is a free research and reference manager. Search for, read and annotate your PDFs. Then review your work, write up and create bibliographies instantly.

A non-profit community site driven by its users' interests.

Emerald was built to help people meet each other. In the modern world it's so fast paced it's often really hard to meet new people.

Postila is a collection of posts. A post is a picture with a short description. You can save anything you find around the web by adding a post.

Standups is a web and mobile (iOS and Android) app that lets remote workers share video and voice updates about their progress with the rest of the team.