Does anyone use feature flags when developing for Plone?
I used it once in a project.
I just created a simple Controlpanel with plone.registry and stored information there.
I've used feature flags in the form of an environment variable which is set differently in different buildout environments (e.g. production.cfg, staging.cfg, development.cfg) to control availability of a feature.
I've been adding multiple profiles into a product for enabling optional features in run-time (yet, disabling may not alway be trivial). Also been playing with zcml feature-directive and enabling features in buildout provided "zcml-additional".
Thanks for the answers 
It looks there there isn't any preferred package for this in Plone. https://github.com/ashcrow/flagon/ looked interesting to me. Waffle and Gutter are more Django-oriented.