If Apple thinks it can woo iPad owners forever with its shiny user-friendly apps and  its cute matching app store, the company is deluded. Amazon and Walmart have challenged Apple to a duel with the release of the Kindle Cloud Reader and Walmart's Vudu streaming site. Beginning a few weeks ago Apple began enforcing its new in-app subscription rules, demanding a 30 percent cut for all sales directly from e-reader apps, as we reported. Companies like Amazon and now Barnes and Noble removed their links from the app store, refusing to pay up to Apple. But that stinks for readers who now have to go through a few extra taps to buy new reads. And it's extra lame for companies looking to sell their wares to iPad owners, who either have to suck it up and give Apple a large chunk of their sales, or forgo the app store link and inevitably lose some lazy readers. So Apple and its app store win, keeping their delights within the app store walls. But with the release of these independent cloud stores, where users can get the same experience without entering the app store cage,  these companies are showing their customers and Apple that they don't need an app store to exist on the iPad.

These services allow Amazon and Walmart to sidestep Apple's 30 percent cut and also benefit their customers, who also avoid any contact with Apple's app store. Both sites were launched as a direct response to Apple's oppressive app store rules. Instead of paying up for direct app store links, Walmart took an alternative anti-app store route, releasing the Vudu streaming site, which bypasses the Apple app store while still providing that same Apple app experience. "It's not an app," Edward Lichty, general manager of Vudu, told Reuters's Alastair Barr. "It's an all-browser experience. But you access it in a similar way."

You can put what looks like an app icon on your iPad, but when you tap it takes you to a streaming site. Similarly the Kindle Cloud Reader site, which like the Kindle app allows users to purchase and store books on the iPad, explains TechCrunch's MG Siegler. "It’s a web-based version of their Kindle eBook reader app. It allows you to read your books from the cloud or to download your books for offline reading thanks to the magic of HTML 5 (or a Chrome browser extension). It looks and works great." No app store, no problem. And just think: if Amazon and Walmart blaze this trail, others might follow.

Not only do companies get out of app store clutches, they make it easy for customers to forget they ever needed Apple. Because they look and work pretty much like an app, this makes things way easier for customers. Before they had to purchase through the web browser. Now you can shop more directly.

Of course users lose some of the convenience, giving Apple a leg up. The web apps just don't work as well as native Apple production, explains Gadget Lab's Charlie Sorrel. "Page turns can be slow when you flick through the book (although if you read at regular speed, the app has time to caches the next page and flipping is instant), and it lacks some essential features." You also don't have unlimited access to all books ever, reminds Siegler. "One thing to note is that the cloud versions (and obviously the downloaded versions) of the Kindle books are still limited to a set number of devices. So if you have your books downloaded to your Kindle, iPad, iPhone, etc, you may be over the limit and will not be able to read them in the cloud." The Walmart Vudu site also has some kinks. It works more like a website, meaning it doesn't stream as well, explains Endgadget's Richard Lawler. "But unfortunately still means that like the PC, it's restricted to standard definition resolution and due to licensing issues is missing any flicks from Disney."

But even with the shortcomings, these efforts should worry Apple. Before they were just losing potential revenue. If more companies follow suit, users might decide the app store isn't all that indispensable after all.