Can I see a history of what has happened?

Yes, you can see a history of what has happened in a project, sprint, team, backlog item, task, etc., by opening the popup dialog for that object and clicking "Show activity" at the bottom of the dialog:

Almost all popup dialogs in Scrumwise have an activity history like this. For example, to see what a team has been doing in a specific sprint, go to the Sprints page, open the popup dialog for the team in that sprint, and click "Show activity". You can also see everything a person has been doing by opening his popup dialog and clicking "Show activity".