Google has their own similar internal software called Snippets that instead of nightly sends out an email once a week, collects responses and sends out a digest along with a web app interface
explanation of software:
http://tech.pro/blog/1490/how-it-works-google-s-snippets
some former google engineer rolled out an open source version of the software that with some factoring, nightly cron jobs instead of weekly and potentially a cleaner user interface for the web app could prolly fit your needs