获取app安装时间
可以变相获取文件创建时间
NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSDictionary *FileInfo = [[NSFileManager defaultManager] attributesOfItemAtPath:path error:nil];//获取文件信息
id firstData = [FileInfo objectForKey:NSFileCreationDate];//获取文件创建
NSLog(@"%@",firstData);
待真机检测!!!!!!!!!!!!!!!!!!!!!!!!
