Please Please do not focus on adding 'features'...The existing application works perfectly on many levels. Please be cautious in selecting the future features.
"Technology is at it's best when it's transparent"
I totally know that this IS your motto and that's why we already have such a great tool.
Just keep up the good work.
Perhaps additional features could be 'add ons', like, for premium users who chose whether they want to enable the feature or not. That way people can chose to modify it to serve their purpose or leave it as is.