Yes, that's what Instacheck (I suppose they call it key-sav) is all about ^_^Is that going to be Shiny? Since I already have a non-shiny Gengar already.
Using a special program to find your "Trainer Shiny Value [TSV]" then finding your egg's "Egg Shiny Value [ESV]"
Each egg is given a different ESV (A number up to 4196 e.g 1232 or 3753) and if the ESV matches the trainers TSV you can essentially make your egg hatch shiny, by giving it to someone with the corresponding TSV.