I’m allergic to cats, but the one sitting on my desk, purring when I pet it, is dander-free, almost 100% plastic, and built and programmed by me.

Frankie the Cat is just one of a five robot-building projects in the new Lego Boost, a $159.99 model-building and code-training kit for kids (and adults). It joins a long line of Lego robotics products, like the stellar Mindstorms Ev3, that blend the build-it-yourself satisfaction of Lego bricks with the nerdy fascination of coding and robotics.

Lego Boost, though, is immediately more approachable and cheaper than anything Lego has done in this space before.

First, it’s a true marriage between your Lego robot creations and the tablet-based app (iOS or Android). Instead of programming through the central Move hub or brick, everything -- from the instructions to the programming of the central brick, sensors, and motor -- happens on the tablet. Lego Boost doesn’t getting mired in tech set-up and the minutiae of actual code. It gets you building and coding through a icon-based drag-and-drop interface as quickly as possible.

The set also uses standard Lego bricks, which means you can add to it from your own collection.

Getting started with Lego Boost is, in one way, at least, just as daunting as it would be with any other 847-piece Lego set. There are 11 plastic bags full of pieces that, since they build five different models (you can only build one at a time), are not really organized in any way. Yes, the tail pieces for Frankie the Cat are all in one bag, but they are the exception.

If I have one criticism of this set, it’s that there is no easy way to find the tiny pieces you’re often looking for, except to go through each bag. To be fair, I chose to jump ahead and build one of the most complex Lego Boost projects, which meant I was searching for dozens of pieces through hundreds of build steps.

Normally, you’ll start by building and programming simple Lego robots and, with each success, the app guides you to progressively more complex projects and coding tasks.

The colorful and inviting Lego Boost app (iOS and Android) starts by showing you a landscape of possible projects. You must complete basic building and coding tasks before you can access the tougher ones, which makes perfect sense when you think of Lego Boost as a fun-filled teaching tool.

The largely visual app does provide some crucial text to help you get up and running. The first step is putting six AAA batteries in the Move hub. As soon as you press the green power button, it connects via Bluetooth to your tablet.

The app drops you into an icon-based programming screen, but your first stop is going to be under the image of two Lego bricks at the top. I do wish the app automatically led me to these instructions, but I don’t think anyone will have much trouble figuring out where they are.

If you’ve ever built a Lego model, you know that the instructions are very much in the IKEA mold: no words, just lots of pictures and color-coded parts. The lack of text-based instruction and even audio guidance can lead to some confusion and the occasional dead-end.

Fortunately, Lego Boost makes the most of these instructions. There are large forward and back buttons to help you walk through each step and, better yet, a slider that lets you effortlessly scrub back and forth through the entire build.

On more complex builds (like my Frankie the Cat and Vernie the Robot), Lego Boost offers much-needed play breaks, letting you program and interact with your model, even as you’re building it.

I did start with a simple model that uses the Move Hub, Interactive Motor and Color & Distance Sensor. The latter two plug into the Move hub via proprietary flat cables. Following the simple on-screen instruction, it only took a few minutes to build the little, faceless Lego vehicle.

With that done, I closed the build window and followed the instructions to construct a simple program for my bot. At this early stage, this entailed dragging and dropping little building block instructions that begins with a big play button and connects to Forward, Back, Left, Right, and Circle blocks, all represented with arrow images, as opposed to words.

Even on this simple robot build, there are stages of programming complexity. Subsequent programming tasks include launching your program by using the motion sensor (by waving your hand in front of it) and making an orange propeller spin.

Many of these programming blocks are self-explanatory, but not all of them, and I think that’s by design. It’s easy to drag a block into your programming chain, run the program (either by pressing a start button on the chain or the large start button on the edge of the programming interface) and see what happens.

There's a lot to learn and experience here.

Yes, you can keep the controls basic, but you can also control the speed and duration of anything that moves. The Color & Distance sensor can be programmed to respond to several of the primary Lego colors. Each of these settings are accessible via simple drop-downs and sliders.

I built a cake out of Lego for Frankie and every time I held it in front of its nose, Frankie would blow out the yellow plastic flame and sing Happy Birthday. On the coding side, this entails having the color sensor respond to the yellow on the candle and then adding in a sound block with the birthday song.

As I started programming Frankie, I found that I could use the Move Hub’s built-in motion sensor to launch my program by turning over the Lego cat or tipping it on its head. Similarly, I could set off a routine by motioning in front of the color and distance sensor or holding a up a colored block that matched the color setting in my programming block.

There are also quite a few sound-based programming options, including recording your own reusable sound bites and applying filters, even though there isn’t a single speaker in the Lego Boost kit. Instead, your tablet will provide every sound your Lego robot makes.

It’s easy to keep things simple, making small robots with basic programs, but there is almost no limit to what you can program.

By the time you get to a build like Frankie the Cat, your programming screen offers eight different code block categories. Along with basic commands like Start and Stop and sensor-based commands, there are nested code blocks that let you build entire subroutines that you can drop into a program as a single block. Since it’s a visually based programming system, this isn't as complicated as it sounds.

The other major models you can build include a dump truck, and auto builder, and a slider guitar that uses the distance sensor to impressive effect. They all look like a lot of fun to build, but, to be honest, after spending more than two days building my model, I think I’ll just sit here and pet my Frankie the Cat.

Lego Boost

The Good

• Lets you build fun and lively robots

• Great app

• Good price

• Uses regular Lego

The Bad

• Could use maybe a bit more text-based instruction in app

• Should come with a way to organize all those Lego pieces

The Bottom Line

Lego Boost is a generally easy to use, yet deceptively powerful Lego-based robot building and programming system.