While the native versus mobile web apps debate continues to rage, one thing is for sure: mobile browsers are going to get a lot more capable, and that means there will be more development of mobile web apps.

Developers of mobile web apps will face numerous challenges, from performance to monetization. But one challenge stands out perhaps more than the rest: building an app that functions and looks good across multiple devices.

In short, depending on the complexity of what you’re building and your attention to detail, mobile web app development can make dealing with IE6 look like a walk in the park.

So Adobe, which has increasingly been moving away from proprietary tools like Flash and embracing HTML5 instead, wants to help. It’s previewing a new tool called Shadow which aims to help mobile web developers see what their apps look like on multiple devices by allowing “mobile devices to synchronously browse with your desktop computer.”

Macworld’s Jackie Dove has the details:

Shadow lets users pinpoint errors, experiment with new ideas and layouts, and view the changes on their devices in real time. It works over a Wi-Fi network, where all devices are connected to the same network. It takes into account the rapid changes in the development landscape, with new devices, operating systems, browsers, and browser versions. Different browsers have varying levels of capabilities, and are enabling new technologies in advance of W3C rules, requiring constant checking to make sure that a design works everywhere, or at least degrades gracefully.

Shadow’s targeted inspection mode lets users do most of the tweaking on their desktop computer without having to interact with the devices. Adobe explains that whereas today, most developers are working via trial and error, with Shadow, they’re able to control revisions from one place.

It’s an approach that could be useful to developers as nothing is as accurate as seeing what an app actually looks like on a target device (as opposed to, say, an emulator). And right now, the price is right; the beta version of Shadow is available for free download on the Adobe Labs website, although it will apparently be turned into a paid product in the coming months as part of Adobe’s Creative Cloud.

Interestingly, Shadow is built on Weinre, an open-source tool that was associated with PhoneGap whose maker, Nitobi, Adobe acquired last year. As Dove explains, Shadow is basically a better (read: less confusing) front-end for Weinre, suggesting that maybe, just maybe, Adobe will be able to prove that it’s committed to wooing the large swath of developers who think of Adobe as the company that built that evil thing called Flash.