Outdated info… Screenr is no longer available, it was shutdown in 2015
Good catch @deanhaycox. Can you give me a link to where you saw Screenr recommended? I’ll follow up. Thanks! 
yup, Screenr is retired on November, 2015 because of Java issue. From then, I found another free screencast application to help recording screen and making edits. It works fine and does not have time limitation in recording, currently it’s my first choice.
I recommend Open Broadcaster: it’s open-source, cross-platform, and very powerful. Slightly steeper learning curve than other screencasting software, but hey, it’s free!