Edited on 2016-02-02
Starting from iOS 6 SKStoreProductViewController class was introduced. You can link an app without leaving your app. Code snippet in Swift 3.x/2.x and Objective-C is here.
A SKStoreProductViewController object presents a store that allows the
user to purchase other media from the App Store. For example, your app
might display the store to allow the user to purchase another app.
From News and Announcement For Apple Developers.
Drive Customers Directly to Your App
on the App Store with iTunes Links
With iTunes links you can provide your
customers with an easy way to access
your apps on the App Store directly
from your website or marketing
campaigns. Creating an iTunes link is
simple and can be made to direct
customers to either a single app, all
your apps, or to a specific app with
your company name specified.
To send customers to a specific
application:
http://itunes.com/apps/appname
To send
customers to a list of apps you have
on the App Store:
http://itunes.com/apps/developername
To send customers to a specific app
with your company name included in the
URL:
http://itunes.com/apps/developername/appname
Additional notes:
You can replace http://
with itms://
or itms-apps://
to avoid redirects.
Please note that itms://
will send the user to the iTunes store and itms-apps://
with send them to the App Store!
For info on naming, see Apple QA1633:
https://developer.apple.com/library/content/qa/qa1633/_index.html.
Edit (as of January 2015):
itunes.com/apps links should be updated to appstore.com/apps. See QA1633 above, which has been updated. A new QA1629 suggests these steps and code for launching the store from an app:
- Launch iTunes on your computer.
- Search for the item you want to link to.
- Right-click or control-click on the item's name in iTunes, then choose "Copy iTunes Store URL" from the pop-up menu.
- In your application, create an
NSURL
object with the copied iTunes URL, then pass this object to UIApplication
' s openURL
: method to open your item in the App Store.
Sample code:
NSString *iTunesLink = @"itms://itunes.apple.com/app/apple-store/id375380948?mt=8";
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:iTunesLink]];
iOS10+:
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:iTunesLink] options:@{} completionHandler:nil];
Swift 4.2
let urlStr = "itms-apps://itunes.apple.com/app/apple-store/id375380948?mt=8"
if #available(iOS 10.0, *) {
UIApplication.shared.open(URL(string: urlStr)!, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(URL(string: urlStr)!)
}
Best Answer
You should always use Keychain to store usernames and passwords, and since it's stored securely and only accessible to your app, there is no need to delete it when app quits (if that was your concern).
Apple provides sample code that stores, reads and deletes keychain items and here is how to use the keychain wrapper class from that sample which greatly simplifies using Keychain.
Include Security.framework (in Xcode 3 right-click on frameworks folder and add existing framework. In Xcode 4 select your project, then select target, go to Build Phases tab and click + under Link Binary With Files) and KeychainItemWrapper .h & .m files into your project, #import the .h file wherever you need to use keychain and then create an instance of this class:
(YourAppLogin can be anything you chose to call your Keychain item and you can have multiple items if required)
Then you can set the username and password using:
Get them using:
Or delete them using: