I don't know about snapseed but I can recommend you some of the best photo editing apps on windows phone. You might want to check out:
Fhotoroom
Fantasia Painter
Camera 360
Pro shot
Nokia Creative Studio
Photoshop Express
Perfect 365
Blink
Photosynth
Photofunia
Phototastic
Lomogram+
Plus all the other Nokia photography apps like Panorama, Smart camera, Glam me etc etc.