Mac: We've seen a lot of apps that mimic Windows' snapping feature where open windows are automatically opened in different positions, but Better Window Manager manages to combine a lot of features into a small package. It allows you to save window states, manage shortcuts, and more.
With Better Manager, you can create application specific window states, assign shortcuts to different states, save various custom sizes, and it works on multiple desktops. More importantly though, it works great on Yosemite, which some of the other options seem to have struggled with. It's cheap at just $3, but there's a free trial on the developers site as well.
Better Window Manager ($3) | via One Thing Well