Best iPhone Apps to Collaborate With Team Members

Freemium

Trello is a web based project management solution.

Commercial

Redbooth (Teambox) is a web-based and on-premises workplace collaboration tool and communication platform.

Find apps to do interesting things:

Synchronize files between two directories.

Converts youtube video into MP4 format and allows you to download it

Play online games with friends

Blocks DOS (denial-of-service) attacks on the server.

Schedule posts on social media which will be posted on specified time.

Share code snippets online