Two Mac apps that I like got gesture-based updates.
First, InShort for Mac received a Yosemite-friendly update with several interface tweaks, including the ability to scale diagrams on a touchpad. The app also has the ability to keep a catalog of locations and mark in which of them the process will be executed or the resource is located, is introduced.
Similarly, Pixelmator also now supports pinch to zoom gestures and the ability to scale objects. Pixelmator is, by the way, an excellent resource for fiddling with holiday photos. Here is a Pixelmator-modified image of some holiday decorations my kids and I made this year. Don't look in Blitzen's eyes too long.