Save NSData File

gistfile1.txt

NSData *file;
file = ...
NSString *path;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
path = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"SomeDirectoryName"];
path = [path stringByAppendingPathComponent:@"SomeFileName"];

[[NSFileManager defaultManager] createFileAtPath:path
contents:FileData
attributes:nil];