We often use tools from the Atlassian suite (e.g JIRA, Confluence etc) but also more lightweight solutions like Trello or others. For calls and chat, we often use Skype and Slack.
We always stay flexible and adapt to the most efficient way of working together.
We always provide a project manager who coordinates the work of the Global BrainForce team. We take great care that the development is always on track with steering meetings.