Ravine at spawn: -1775820978
Ravine is a new type of randomly generated landscape, which can be useful to the player because of resources that can be found there.
End City seed: 57857190
End City is a structure that rarely generated in the End, but can be found quicker using this seed.
Woodland Mansion seed: -396676922
Woodland Mansion is a new type of structure that were added in Minecraft PE 1.1.0 and can be found only in the roofed forest biome.