Amazon is continuing to go after iTunes by redesigning its mobile MP3 store to better target iOS users. The company announced on Thursday the relaunch of the optimized store "specifically for iPhone and iPod touch," allowing customers to browse and buy MP3s directly from within mobile Safari—no native app necessary. The measure doesn't just help iOS users who prefer Amazon for their music purchases—by modifying its mobile Web store, Amazon is getting around Apple's demand for 30 percent of the sales if Amazon were to sell music through a native app.

"Since the launch of the Amazon Cloud Player app for iPhone and iPod touch, a top request from customers has been the ability to buy music from Amazon right from their devices," Amazon said in a statement. "For the first time ever, iOS users have a way to do that."

Amazon's new site for iPhone and iPod touch is built on HTML 5 and gives access to daily deals like $5 albums, $0.69 songs, and free music from up-and-coming artists. It can also offer individual recommendations based on your past purchases. I gave the Web app a quick spin to see whether it's as great as Amazon claims. It turns out that the new store is indeed very usable on the iPhone, though it requires you to have downloaded and installed Amazon's Cloud Player app if you want to be able to listen to your purchased music right away.

Unsurprisingly, the Web store UI is touch-friendly, allowing you to swipe through selections without annoying page refreshes. If you're already an Amazon MP3 customer, though, the actual functionality isn't too different from what you're already used to—you can purchase individual songs or full albums (sometimes at a huge discount compared to iTunes), and the search function allows you to dig deep for music that might not otherwise be highlighted on the main page.

My biggest interest was what happens when you purchase a song. In order to do so, you must enter your Amazon password (even if the site already recognized you when you showed up), which may be a challenge if you're like me and use 1Password to store that information. Still, once you enter it, the purchase happens quickly and your song(s) are automatically transferred to your Amazon Cloud Player library.

The catch (which, admittedly, isn't a huge one) is that Amazon Cloud Player is the only way you can download the music to your phone, and if you don't already have the app, you'll have to go to the App Store to get it. Without the app, tapping the orange "Play or Download" button from Amazon's MP3 store confuses the iPhone; it will pop up an error about the URL being invalid and push you to the iTunes Store. If anything, it should probably send you to the App Store to get the appropriate app, but I can see this being confusing to new users.

That said, if you do have the Cloud Player app, the music should already be there by the time you manage to launch it. You can then either stream your MP3s from the cloud or download them to your device. Downloads are still stored within the Cloud Player app; you can't transfer them to Apple's Music app unless you do so on the computer and re-sync your iTunes playlists.

This is obviously inconvenient for those who only manage their music through iTunes, but there are plenty of Amazon MP3 fans out there. In that case, the new Web-based store is a very usable way to shop for and download music on an iPod touch or iPhone, and I didn't run into any noticeable glitches. Have you run into functionality or usability problems? Let us know in the comments.