As someone who blogs about iOS devices and software, I take a lot of screenshots. Thankfully, Apple has always made this dead simple to do on their devices—all it takes is a click to save a screenshot to your photo library. But sometimes that doesn’t give you the full effect. Sometimes you want to show how something will actually look on a device. Until today that has meant exporting your screenshot to a laptop, firing up Photoshop, and inserting it into a blank iPhone frame. It was often a few steps more than many reviewers wanted to take.

With PreviewMaker, just released in Cydia, they no longer have that excuse. This new app from FreeAppl3 and Subywrex provides a quick, intuitive way to showcase your iOS screenshots. Most importantly, it allows you to do it all without ever leaving your device.

Take a quick screenshot and open the app, and you’ll be greeted with the option of choosing a black or white iPhone frame (other device images are planned for future updates). Simply tap the screen area to open your photo albums, from which you can choose a screenshot to display in the frame. (All of the images in this post were created with PreviewMaker.)

With your image set, you can add in a glare effect to imitate the display glass, and also have an option to add a watermark—the app comes with a default image (see below) but allows users to load a custom watermark as well—to protect and promote your images. Once done, you can save the image to your camera roll, email it, or share it to a variety of online services like Twitter, ImageShack, or Dropbox.

I did notice a couple of small bugs in the app: once in a while, the popup that confirmed I’d saved my image could not be dismissed, and the app icon itself has a minor cosmetic issue; while the icon features rounded corners, it sits in a square box that I’m guessing was meant to be transparent. Not a huge issue, just an odd one for an app that nails so much of what makes iPhones look so great.

Those very minor quibbles aside, PreviewMaker has immediately changed the way I work, and very much for the better. It’s a wonder that it took so long for such an app to be made, but now that it’s here, there is no imagining mobile iOS blogging without it. It’s really that good. Find it in Cydia, where it can be had for $1.99 on the modmyi repo.

(Update: Although similar to Mac App Store app Screentaker, PreviewMaker was rejected from the iOS App Store before landing in Cydia. According to FreeAppl3 the rejection was due to the iPhone imagery; Subywrex, however, claims in a Modmyi comment that the app was rejected for “being too awesome.” He also mentions that a planned update will bring the ability to add Display Recorder video to the device frames.)