The idea of getting kids to program is a good one; computers are, after all, at the heart of modern life. I've always argued that the best way to learn to code is to solve a practical problem, not abstractly, and programmable toys (particularly robots) give kids real world objectives to solve. Though most of the robots on the market are programmable in much the same way, there are huge differences in the quality of the experience, largely depending on the capabilities of the robots, and the depth, quality, and character of the pedagogy in the apps. In short, some take a clinical (almost sterile) approach, others go all cutesy, while others strike a balance that mixes skill building, concepts, and entertainment.
First off, be dubious of claims that the same robot works for toddlers and tweens. Frankly, I don't think programming is important as a pre-literacy skill, but where it is incorporated in play it should be age-appropriate and there is no one-size-fits-all solution.
The Fisher-Price Code ‘n Learn Kinderbot ($ 34.99) is a robot with simple, logically arrayed buttons that can be programmed by a four year old. Simple directional instructions are entered by clearly labeled buttons. At first, the play will likely be random, but as the children gain experience through "cause and effect" they will learn to make the robot go where they want it to.
Once you move to robots for older kids, keep in mind that these almost all require a smartphone or tablet to work. Make sure your choice works with hardware you have on hand.
For early-school year kids there are a number of good options. Dash ($149.99) by WonderWorkshop remains at the top of the list. It can do more than many toy-robots (particularly when you add-in optional playsets like the ping-pong ball launcher or drawing set). It is attractive, has a cute voice, but most important, has a variety of free apps that level-up the child's experience. If you bought this last year, and it has languished (as toys often do after the initial rush) it makes sense to dust this one off and see if there is software available that your child hasn't yet tried, or wasn't ready for when the robot came into the house. Sometimes, al little parent-child sharing can reinvigorate and extend play.
One of the most common capabilities of toy robots for older kids is the ability to draw using a magic marker as the robot moves. Most have a feature that can lower a marker, move the robot and draw a line, and then raise the marker. Unfortunately, even if you're using non-permanent markers (most do) such a robot can make quite a mess if it marks up the rug. So, if your new robotic friend has this capability, make sure you and your child understand where it can be used and how a simple programing mistake can lead to disaster.
The most common robot found in a lot of homes is the Roomba vacuum. This year iRobot, the company behind the Roomba, has introduced a toy robot, the Root ($179) that is very well tricked out with sensors and even has a built in way of drawing (more about that later). If you've got a metal door on your refrigerator, it can even climb the wall using magnets. However, though it can do many of the things a robot vacuum needs to be able to do (respond to the edge of a step, move various directions, make sounds, and even display lights), its overall look is pretty sterile, white, less like an Apple product, and more like something that might be polishing the floor on the DeathStar. This limits its play-power outside of the classroom, as using it feels a bit more like "work", than "play".
Sphero makes really interesting robots. Most of the Sphero robots look like balls, so it is surprising when you see that they can be programmed to move precisely. They have several models from the Mini to the Spark. Interestingly, the out-of-the-box experience focuses on driving the robots like an RC vehicle. Kids may miss the incredibly rich programming environment, so this is a good opportunity to show your child the deeper capabilities of the toy.
If you've got a Lego builder in your house, Lego's Boost robotic kit is a perfect gift for tweens. Unlike the premade robots, above, Boost's build-it-yourself robots can be much more complicated and powerful because of the mix of motors and sensors included. Also, since the parts work with other Lego sets, the kit makes it possible for kids to dream big and produce results. The instructions are well explained without talking-down or being over-cute.
My favorite coding toy of the year is the Arcade Coder ($159.99) from Tech Will Save Us. Rather than the "toy" being a robot, it is a light-peg-board like device that kids use to create art work, play, and ultimately create old-school arcade games. Virtually every bit of this product is above average (including the time it takes to download its firmware which is unfortunate). Kids program the device on iOS devices (version 11 & up). It is also where they watch videos that help them gain expertise. In one mode the board can be used in conjunction with the app to create binary artwork; its grid of buttons light up and can be set to different colors individually in the app. But, things get more interesting with the games. Three come built -in, games that were available when I got my first computer in the early 80s. After playing for a while, kids are invited to change variables that affect game play and cosmetics through the app. Then, using the same sort of visual programing style used by most of the robots, above, kids are guided to make their own multi-player games can be played on the electronic board. By the way, the design of the board is pretty remakable. Not only is the grid comprised of dozens of light up buttons, but the backside is transparent, and labeled, so kids can see what is underneath! There is also a timeline of video gaming stenciled onto the circuit board. I can't say enough about this Arcade Coder. For kids 10 and up interested in computers and gaming it is a must-have.