Swift:

if let url = URL(string: "mailto://[email protected]") {
    if UIApplication.shared.canOpenURL(url) {
        UIApplication.shared.openURL(url)
    } else {
        print("Cannot open URL")
    }
}

Objective-C:

NSURL *url = [NSURL URLWithString:@"mailto://[email protected]"];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
    [[UIApplication sharedApplication] openURL:url];
} else {
    NSLog(@"Cannot open URL");
}

These are URL schemes supported by native apps on iOS, OS X, and watchOS 2 and later.

Opening link in Safari:

Objective-C

NSString *stringURL = @"http://stackoverflow.com/";
NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];

Swift:

let stringURL = "http://stackoverflow.com/"
if let url = URL(string: stringURL) {
    UIApplication.shared.openURL(url)
}

Starting a phone conversation

Objective-C

NSString *stringURL = @"tel:1-408-555-5555";
NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];

Swift:

let stringURL = "tel:1-408-555-5555"
if let url = URL(string: stringURL) {
    UIApplication.shared.openURL(url)
}

HTML

<a href="tel:1-408-555-5555">1-408-555-5555</a>

Starting a FaceTime conversation

Objective-C

NSString *stringURL = @"facetime:14085551234";
NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];

Swift:

let stringURL = "facetime:14085551234"
if let url = URL(string: stringURL) {
    UIApplication.shared.openURL(url)
}

HTML

<a href="facetime:14085551234">Connect using FaceTime</a>
<a href="facetime:[email protected]">Connect using FaceTime</a>

Opening Messages App to compose an sms to recipient:

Objective-C

NSString *stringURL = @"sms:1-408-555-1212";
NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];

Swift:

let stringURL = "sms:1-408-555-1212"
if let url = URL(string: stringURL) {
    UIApplication.shared.openURL(url)
}

HTML

<a href="sms:">Launch Messages App</a>
<a href="sms:1-408-555-1212">New SMS Message</a>

Opening Mail app to compose an email to recipient:

Objective-C

NSString *stringURL = @"mailto:[email protected]";
NSURL *url = [NSURL URLWithString:stringURL];
[[UIApplication sharedApplication] openURL:url];

Swift:

let stringURL = "mailto:[email protected]"
if let url = URL(string: stringURL) {
    UIApplication.shared.openURL(url)
}

HTML

<a href="mailto:[email protected]">John Frank</a>

You can also include a subject field, a message, and multiple recipients in the To, Cc, and Bcc fields. (In iOS, the from attribute is ignored.) The following example shows a mailto URL that includes several different attributes:

mailto:[email protected][email protected]&subject=Greetings%20from%20Cupertino!&body=Wish%20you%20were%20here!

Note: Compose email dialog can also be presented within app using MFMailComposeViewController.