[UIApplication sharedApplication] openURL

[UIApplication sharedApplication] openURL

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"mailto:"]];
 
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://"]];

08[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel://"]];
 

结束通话后自动返回到应用：
UIWebView*tempWebview =[[UIWebView alloc] init];
NSURL *telURL =[NSURL URLWithString:@"tel:phoneNumber"];
[tempWebview loadRequest:[NSURLRequest requestWithURL:telURL]];
[self.view addSubview:tempWebview];
 
可能不能通过审核
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"telprompt://phoneNumber"]];

调用浏览器 safari
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"http://www.google.com"]];