A new round of updates to Brewtility brings a host of fixes, enhancements and new features. Among them is an all grain to extract converter.
This doesn't work for all recipes, but when viewing any recipe with base grains that have extract equivalents you should see a new icon (shown below.)
Clicking this icon will convert the base grains to extract equivalents and automatically adjust the amount to keep the same original gravity.
Currently this converter assumes that you're doing a full boil, so it doesn't adjust the hopping schedule at all. Eventually there will be an option for a full or partial boil and the hops can be adjusted accordingly. But this is a good step and a requested feature that should be quite useful.
Enjoy!