Flipbook HD is an iPad app for anyone with a serious interest in 2D animation. I say serious because, while this particular app doesn’t have quite the fidelity someone might want to make a professional animation, it gives you all the tools you need to actually animate and publish the video for a movie. The learning curve attached to it is a bit steep though.

Since this isn’t a game, our standard categories don’t really apply. As for the app’s audio, there isn’t any. I can talk about the GUI, but I can’t even talk about how well the app works with adding music or sound effects for your animation, because it simply doesn’t do anything with sound.

While Flipbook HD doesn’t allow you to attach any audio to your creations, it does give you a wide variety of tools to make the images you want. Each of the application’s various tools have easily identifiable icons and the overall feel of the app takes from the drawing-table design, complete with a single sheet of paper with a light box behind it. Put simply, as far as how well Flipbook HD conveys what it can do from a UI design standpoint, it gets the job done.

Flipbook HD is designed to simulate an actual drawing table where a 2D animator or artist will build the world in multiple layers and then move to the next cell where a new, but similar, scene will be drawn.

The tools available should be familiar to anyone who has tried out even the most basic art program. The app provides a brush tool that lets you adjust the size, softness and even pressure of the lines you draw as well as the standard assortment of eraser, shapes, text, eyedropper and selector (both lasso and square) tools. For your coloring pleasure, Flipbook HD gives you a color selector that lets you adjust the RGB values from 0 to 255 as well as an alpha channel percentage to adjust the transparency of the paint you are applying.

So, if you’ve handled even MS Paint, you should be able to throw together even a basic image to fool around in, but after that, things get a little more complex since you will want to make sure you break your work into multiple layers, or tracks as Flipbook HD calls it.

Let’s say you have a picture of someone throwing a ball on a grassy field. Well, while you will have to redraw the ball-throwing in the different animation cels, you don’t want to keep drawing that same background over and over again. So, you put that together on the bottom-most track. With a few more taps, you can make that static background span the entire movie.

As for the ball-thrower, the standard 2D animation technique has you moving from cel to cel and redrawing that character in a slightly different pose until the scene plays out. Much like the non-digital versions of this action, you can set up your drawing space so that the previous cel is shown through the current cel. This allows you to trace whichever lines didn’t move and know how much to change the ones that do. At this point, anyone familiar with how 2D animation happens should know what’s going on and see how Flipbook HD seems to do a good job of mimicking the real-world process.

In an attempt to make matters a little easier and cut down on the redrawing, Flipbook HD has the ability to add Keyframes. Again, if you are familiar with animation, this time in the computer animation side of things, you should know where this is going. The idea is that instead of drawing each cel of the character throwing the ball, you only draw the major points in the process, like the first scene where the arm is at the character's side, then one later where it is reared back, and then one where the ball actually leaves the thrower’s hand. With the magic of computers, the application is then supposed to fill in the blanks and get the arm smoothly between the different locations in the desired amount of time.

Unfortunately, I could never really get this feature to work. Despite multiple re-reads of the tutorial and plenty of time playing around on my own, I could only get the process working once … and quite frankly, I don’t know what I did then, I wasn’t able to reproduce it. So, does Flipbook HD do keyfame animation? Yes, can I tell you how? Not really. I did think it was odd that, instead of trying to morph one cel into the next over the desired amount of time, you are instead selecting the part of the image you want to move and rotating, resizing and moving it. As a result, the best I could do was something that looked like a Monty Python animation involving parts of the image on different tracks moving independently of the whole body and in ways that simply don’t look natural.

Okay, so, this app does quite a lot, and it has to in order to produce a somewhat complete 2D animation workstation. Unfortunately, it has a few issues that makes Flipbook HD a hard sell.

For one, you simply don’t have the control and fidelity you need in order to draw a nice, detailed picture. While you can change the brush to a thin line, you are still using your finger to do the drawing. Thinking that a good stylus would solve this problem, I finally got around to picking one up for my iPad, but I found I still had the same problems, it just isn’t exact enough to get the job done.

That’s okay though, Flipbook HD has the ability to import photos. So, instead of trying to draw the various items on the iPad, you can draw them separately and import them into the program. Except, I’m sorry to say that bringing an image into Flipbook HD almost always caused the app to crash, and that’s not the only time either. I found myself not being able to work in the app for more than five minutes at a time before some command I gave it caused me to have to relaunch Flipbook HD. Thankfully, the app seems to save frequently, so you won’t really be losing anything, well, except for time and patience, that is.

Flipbook HD takes a good bit of learning. Even if you are familiar with 2D animation and the overall process, figuring out how to do what should be simple processes in Flipbook HD can be a little tricky. Tasks like moving the contents of one track to a different one, or stretching a cel across multiple time slots all require a bit of effort to figure out, even if you’ve been in the app for a while.

Flipbook HD comes with a tutorial movie for you to tap your way through and supposedly get a good handle on the app’s different features. It does a good job of teaching the basics, but I found that it could have been better, and even when I was done with it, I had to go back to it on multiple occasions. The app just has a clunky feel to it and there are times when it feels like what should be basic operations, like deleting cels, take too many taps, or in that particular case, a tap, a tap-and-hold and then another tap (and one more tap if you are done deleting cels).

With all of the complaints I have about Flipbook HD, when you get used to its toolset and how to do everything, something I’m still struggling with, it isn’t all that bad. It does what it says it does, it just might not be the most streamlines process.

With Flipbook HD, you are able to doodle a scene and play out some story much like you might do in the corner of a notebook. I can even see it as a good learning tool to teach a younger kid how animation works. It can even export your movie to your iPad’s album, e-mail it to a friend or post it to the Flipbook HD website.

All that being said, the app crashes a lot. I said this above, but it bears repeating. There are several tasks that I can do that will cause the Flipbook HD to die every time, but they pale in comparison to the number of crashes I experience when avoiding those known pitfalls. As it is now, I simply can’t recommend Flipbook HD. Maybe a later release that makes the application more stable will do the trick, but version 1.0.1 (the latest at the time of this writing) has too many problems to ignore.