From time to time I have to show my bosses what our team has done in the last period. We use 2 weeks as our sprint lenght (although we're not following scrum strictly).
Anyway, I was looking for a way to summarize the activities of the team, and instead of trying to remember, or having to write annotations for the next report, I just crafted this nifty little git log command which allows me to know which branches have been merged to master in the last 2 weeks.
So now, 5 minutes before the meeting I just run it and see what I have to debrief to my bosses (or other teams in the company).
git log --since=2.weeks.ago --merges --branches=master --first-parent --graph --pretty=oneline | sed -e 's/.* from/*/'
Try it in your repos, and see how it works for you. For me it pretty much nails it.