1.跳转到AppStore评分

应用地址是关键:IOS 设备，手机搜索应用，拷贝链接

NSString *appStr =@"https://itunes.apple.com/cn/app/%E9%91%AB%E5%AE%A2%E9%80%9A/id1227457584?mt=8"";

[[UIApplication sharedApplication]openURL:[NSURL URLWithString:appStr]];

2.应用中调用系统写邮件

[[UIApplication sharedApplication]openURL:[NSURL   URLWithString:@"mailto:example@example.com"]];