Add to HomeScreen WordPress plugin invites your readers to add your blog as an icon / web app on home screen of their iPhone, iPad and iPod touch.
This plugin works very well on responsive theme without any customization. However, if you do not have a responsive template, you can make the plugin works by increasing dimensions of the floating balloon on the plugin options page because it may be very small on non responsive theme. I advise you to fill out recommended values mentionned in the options page.
Basically, you have two ways to let visitors browse your blog: on Safari or in a separate window.
Application names on the home screen are limited to a maximum of 12 characters, so anything beyond that will be truncated. Try to keep the title of your application under 13 characters on the iPhone if you want to prevent it from being cut off. Fortunately, there is an option in the plugin to customize your application title, it can be very useful especially if the title of your blog is too long.
Yes, and the icon will be displayed correctly depending on both pre and post iOS 7 devices.