I have been sending different flavours of the Agile A4 Sprint Report at the end of each sprint for more than 5 years since I read from it in The Professional Product Owner book. In each email I also add a few observations on what can be improved and suggests a couple of actions for the following sprints (the Lean way). Quite an useful tool indeed.
As Ralph Jocham says: «I am a big fan of the Toyota A3 Reports (…) So I was wondering how you could use them for reporting when using Scrum. The result is what I call the «Agile A4 Sprint Report» as it fits nicely on a page«.