With Filestar you get 106 different skills for working productively with Sketch/Skencil format (.sk) files.
About .Sk
Name
Sketch/Skencil format
Extension
.sk
Format
Binary
Category
Vector Image
Developer
Skencil
Description
This format is a vector images file in the Sketch Drawing program, which serves to edit and create interface designs, applications and software shells. SK-files contain objects and layers which can be edited independently of each other.