How can I interact with other users?

When you're in a trip, click the small chat icon in the top right corner to start a conversation. 

Communication is only possible with users who also have a profile in GTP.

Now click on the blue paper icon to start a new conversation or search for an existing one on the left.

Now enter the name of the user you want to contact and under "Select Quote" select a trip to which the message should relate.  

Now enter your message.  

As soon as the message has been sent, the recipient receives an email with the option of calling up the message directly from this email.

In GTP you will know that you have received a message when there is a red dot on the chat icon.