Working on an icon for your new iPhone 4 or iPad app? Fresh from WWDC 2010, Cocoia have updated their PSD resource file to include not only the original iPhone/iPod touch and iPad dimensions, but the new iPhone 4 114×114 Retina Display resolution as well:

Again, if you appreciate it, tweet this to help your fellow designers and developers make nicer icons for iPhone 4 (and beyond).

As someone who admittedly skips over anything with a poor icon in the App Store, here’s hoping Cocoia’s generosity — and passion for iconography — is widely embraced.

Go grab it via the link directly below.

[Cocoia]

If you’re interested in iPad design or development, the internet is already offering up resources for you, including interface recommendations, icon templates, and galleries of Apple examples. And why not? The same people who love every pixel of interface on the iPhone are finding 1024×768 reasons to pour over the iPad’s beefy new canvas as well.

First up, Gizmodo highlights some of Apple’s new iPad Human Interface Guidelines (HIG) which suggest developers “think different” and not just big when it comes to the iPad. They have to “just work” no matter how a user holds the iPad, portrait or landscape, and they should remain just as focused and uncluttered as iPhone apps. It should be easy to share, both in terms of several people using the app on the same devices, and moving data back and forth from the app. Real world look and feel is encouraged; making contacts look like a book gives it tangibility. Multiple multitouch gestures are your friend (there’s a reason NOVA let the player touch the screen and turn the door latch). And while it is a computer, it shouldn’t present the user with file-systems or other computer management tasks.

Next, Cocoia has been generous enough to share a downloadable Photoshop PSD template for iPhone and iPad icons, everything from giant 512×512 to standard iPad and iPhone sizes, to iPad Spotlight and menubar variants.

Last but not least, developer Frasier Spears has painstakingly assembled a Flickr gallery of every iPad UI element he could get his screen-shot on, and presented them with commentary. No better way to get started than by checking out what Apple’s done so far.

UPDATE: Force Quit has changed in iPhone 3.0. Check out our new how-to!

Those of us who rock Mac OS X know all about the “Force Quit”. For Windows users, think killing an application via Task Manager. They’re both ways to shut down non-responsive or otherwise rogue applications from freezing us out or just slowing us down. For iPhone users, well, we don’t have to worry about that, do we? (Remember Apple mocking Windows Mobile for multitask management?)

Well, since MobileSafari, MobileMail, and other Apple apps do multitask and run in the background, it turns out we iPhone owners do still need to worry about it. And with the App Store providing all sorts of new and potentially greedy applications to strain the more limited resources of Mobile OS X, it’s certainly important functionality to have.

So what can we do? Luckily, Apple built in an solution.

Hold down the “Home” button for about 6 seconds. Your resources will then be freed up, and you’ll be dropped back to the Home Screen ready for a fresh, clean start.

Faster and easier than a full reset, it can get you out of an App jam or improve the “snappiness” of your iPhone in general.

Note: if you have tabs open in MobileSafari, the cached pages will be cleared, but fret not, MobileSafari will re-load the pages off the net for you as soon as you relaunch it.

(Thanks to Antony for the screen shots)