PlayOn, the service that allows you to view streaming media from the web and PCs on a variety of devices, is finally headed to the iPhone as of tomorrow. It originally planned to release an iPhone app via the iTunes App Store, but due to approval delays by Apple, PlayOn has instead developed a mobile HTML5-driven web app.

The release of the web app, which currently only works with the iPhone and iPod Touch, marks PlayOn’s first foray into mobile devices. (I didn’t have an iPad to test the app on, and I’m currently awaiting confirmation if it works on that device.) The app doesn’t work on the iPad yet, but PlayOn is working on supporting it over the next few weeks. (If you’re impatient, check out Technologizer’s Jared Newman’s workaround for getting it to work on the iPad.)

Users simply need to install the latest version of the PlayOn client on their Windows PC, then log into on their iPhone while connected to their home network. The mobile app then searches the user’s local network for PlayOn servers, and upon discovery, it grants full access to Hulu, Netflix, Comedy Central, Revision3, and other PlayOn content channels. Eventually, users will be able to log onto their PlayOn servers from anywhere by using their WAN (wide area network) IP address.

PlayOn costs $39.99 for the first year, and $19.99 every year thereafter. Alternatively, users can make a one-time payment of $79.99. After installing the client, users can access content via game consoles like the Xbox 360, Playstation 3, and Nintendo Wii, as well as through computers and other devices compatible with the DLNA streaming media standard.

For Hulu lovers, the release of the web app means that they can get access to the service’s content library without paying $10-a-month for Hulu Plus. Admittedly, PlayOn’s interface isn’t as slick as the official Hulu iPhone and iPad apps. Hulu is also constantly battling with PlayOn and similar services like Boxee to block access to its content — so it’s important to note that access to Hulu won’t always be guaranteed with PlayOn.

While it wasn’t the company’s initial plan, it’s definitely better off with the mobile web app, instead of an iPhone app that’s locked into Apple’s ecosystem. The web app can easily be updated to support other phones and devices eventually, and it could be a much simpler way to access PlayOn content from other computers, compared to previous methods.

PlayOn’s official statement on the iPhone app rejection is below:

PlayOn received approval from Apple in June of 2010 for our application for the iPhone, iPod touch and iPad. Set to launch on July 15th, this app was developed to allow existing PlayOn users to stream online video content and personal media via a home networked PC using the PlayOn software client.

It has now been followed by a notice from Apple that the application has once again gone into review.

Other similar iPhone apps have been approved for the marketplace and can currently be downloaded, including SlingPlayer Mobile and iDisplay, so we’re confident that we can work through this issue with Apple and hope to be able to launch the application on the App Store soon.

It’s strange to me that PlayOn is still pursuing an iPhone app, because the web app works extremely well from my testing over the past few days. It’s a testament to the power of HTML5, and the returning focus on iPhone web apps. (Consider the web app store OpenAppMkt, which offers many features found in the iTunes Store — except it’s outside of Apple’s control.)

On my 802.11G home network — which runs at 54 megabits-per-second, and is typical for most consumers — Hulu and Netflix video loaded up within 15 seconds on the iPhone 4, and the video quality looked excellent. The app gave me trouble connecting to Netflix, and that’s something that I hope is resolved soon. (As of this morning, Netflix access works fine.) PlayOn is technically the only way to get Netflix streaming content on your iPhone right now — at least, until Netflix brings out its official iPhone app this summer.

Navigating through the app’s many menus was zippy, and while the interface had a few bugs during my testing, a PlayOn representative assured me that they were working on squashing them.

Having been a PlayOn user for some time, the release of the app strikes me as something that’s better for existing users than it is for newcomers. Now instead of dealing with PlayOn, new users can pay for Hulu Plus, and wait for the official Netflix iPhone app to be released. And given that PlayOn is a sort of workaround solution to get access to video content, going through the official channels will be far more reliable, and less of a headache, for general users.

Media Mall Technologies, the company behind PlayOn, was founded in 2003, and is based in New York, NY.