Don’t ask me which site I came across this on, because my web meandering has taken on many paths at this point and I’m a bit sleepy. 
Freshout, the original creators of the Flutter plugin for WordPress have planted a seed. Being an equally passionate Drupal and WordPress developer I find it encouraging to see the phrase: “Flutter is CCK for WordPress.” Allelujah!
I had to see what it was all about so I instantly downloaded the plugin and started looking for documentation. It is scarce! Thanks to Devin at WordPressTheming.com for providing a few video tutorials on implementing Flutter for a design portfolio.
In the end I think that Flutter is a robust solution for CMS enhancements to WordPress, but I’m hoping the WordPress community will come up with something better. Perhaps Matt Mullenweg will collab with Freshout?
Read more in Freshout’s: “Path to Flutter”
Hi Damon. It looks like development has stalled a bit on Flutter (no updates in the last 6 months)- but there’s quite a few other projects that have picked up the slack.
Pods CMS seems to be one of the most popular, but there’s quite a few others for building custom write panel solutions.