Do you have a terrific app concept in your head, but don’t know how to explain it, let alone create it? Fluid UI might have the tool for you.

Mobile Mockups lets you design apps using only a Web browser.

Featuring drag and drop technology, Mobile Mockups offers an easy and effective way to design iPhone, iPad, and Android apps in minutes. And because it uses HTML5 technology, it is accessible through Mac, Windows, and Linux, and supports Chrome and Safari with Firefox support coming soon.

To get started, you’ll be asked to setup an account on the Fluid UI website. But, don’t worry: you can create a few designs for free.

Now the fun begins.

Fluid UI

Using the site’s live editor, you can select objects to include on your design. Available items include backgrounds, layouts, bars, buttons, controls, and more.

Adding new objects is as easy as dragging them into your virtual device and then positioning them accordingly.

Don’t like how your mockup looks? No problem, as you can easily delete objects and start again.

It really works!

According to Fluid UI’s Ian Hannigan, their goal was to create an easy and inexpensive tool for users to validate their app ideas and designs during the early stages without barriers.

Indeed they got this right. During my initial tests, I found the service worked as expected. In fact, it pretty much exceeded my expectations.

I especially like the tool’s export capabilities, which makes sharing your designs a breeze. You can export your designs in PDF, HTML, and image format with native export expected soon.

Plus, since Mobile Mockups uses touch and gesturing technology, you’re able to test each design on your iDevice, which is unquestionably cool.

Did I mention how cool this was?

Fluid UI - Lots of features

Fluid UI - Lots of features

Mobile Mockups is available in three packages: Starter, Team, and Agency.

With the $29/month Starter package, you can design three separate projects at the same time and upload 250MB of data.

Team ($49) offers 10 live projects and 3GB in uploads.

Finally, the Agency package ($129) gives you 30 ongoing projects, plus unlimited uploads.

Each package offers unlimited sharing and discounts are available if you commit to a 12-month commitment.

Fluid UI’s new tool comes highly recommended for those would-be app developers that haven’t mastered X-code and know little about app design in general.

Our advice is to try it out and see what you think. We don’t think you’ll be disappointed.

While you’re at it, be sure to check out our report on TinkerLearn, a new way to learn how to develop in iOS that arrived earlier this month. Plus, there is always TestFlight live.

What are you waiting for? Go design your first app!