An increasingly common activity in iOS apps is retrieving data from web services. This is particularly true when the app is really an extension of the functionality offered by a web-based application. One challenge in doing this is that some key classes often used in Mac OS X applications are not available on the iOS platform: specifically, NSXMLDocument. This turns out to be a blessing in disguise because NSXMLDocument is not very performant. Instead, I use TBXML, an excellent lightweight XML parser.
Even though most modern browsers can remember your usernames and passwords for you, it is nice for a web application to allow an individual to return to a web site and be automatically logged in without having to submit credentials every time they do so. Implementing "Remember Me" with the Istarel Workshop Application Framework requires several code blocks, and this article assumes that basic security has already been implemented in the application.
For the applications I build, user passwords are (usually) initially system-generated, which means they appear to be an inscrutable mess of letters and numbers. Most users want to have some control over their own passwords, which means I need to provide a form that lets them change it.