See Below Code
1) Download ZipArchive from Link for ZipArchive API
2) Drag into project.
3) Add to project existing framework libz.1.2.3.dylib (last version).
Import #import "ZipArchive.h"
header in your ViewController
ZipArchive *za = [[ZipArchive alloc] init];
if ([za UnzipOpenFile: filePathToUnzip]) {
BOOL ret = [za UnzipFileTo:filePathtoBePlacedAfterUnzip overWrite: YES];
if(ret)
//unzipSuceesfully.
else
//Failed to Unzip.
[za UnzipCloseFile];
}
[za release];