Amazon's $25 Flex might be the most important device the tech giant has released in years. The unobtrusive gadget plugs directly into an outlet, offers a fully featured Alexa (even if she sounds a little tinny in its tiny speaker) and sports a USB port for either a nightlight or motion sensor attachment (each a $15 extra).It's simple, clever, cheap and paints a picture of your future smart home -- where Alexa is always a wake-word away, ready to assist with practical needs like lighting a hallway at night, automating your lights or upgrading your security. Amazon still isn't assuaging the concerns of customers rightly worried about privacy, but it is positioning itself with the Echo Flex to bring Alexa-powered home automation to the masses.What it's notThe Echo Flex is a solid gadget, but don't play music on it. The speakers are purely functional, and you can hear Alexa clearly across the room, but music sounds very small coming from its 0.6-inch speaker, like a dated phone speaker.So if you don't have a smart speaker, the Flex probably is a worse entree into the field than an Echo Dot or Nest Mini-type budget speaker. But if you're already bought into Amazon's Echo-system, the Flex offers a cheap way to expand Alexa's reach into the less central areas of your home -- whether it's a hall, entryway or bathroom. If you catch yourself in parts of the house where your Echo is just out of range, the Flex is a perfect solution.What it isSo what does the Flex bring to the counter that a 50%-off Dot doesn't? Well first off, the Flex doesn't actually take up counter space. That means Alexa can suddenly live in more spaces, out of sight and out of mind -- until you need a question answered or a smart shade closed.Besides the plug-in design, the Flex also features a USB port for a phone charger or the night light and motion sensor modules -- each of which costs an additional $15. I tested out those accessories, and both added nice additional features, expanding the possibilities of how you can use the Echo Flex. The color-changing and dimming night light works as expected, but the motion detector cleverly slips home automation tricks directly into an Echo device. Popping open the Alexa app to set up automated routines felt exciting, like the earlier days of smart home devices, when people needed platforms like IFTTT to integrate their various gadgets.The Flex's modular design cracks open the door for Amazon to meet common needs in the home -- much as the clock on the Echo Dot did. It's a low-key but high-potential approach to smart home devices, and this is the first time I feel like Amazon might make a compelling play not simply for voice assistant dominance, but also for smart home automation superiority -- which is particularly notable given how separate the voice assistants of today have felt from the niche Zigbee and Z-Wave-dependent smart home devices of 10 years ago.Downsides of a downsizeSo $25 might seem like a great deal for an Echo device -- and it is -- but Echo Dots routinely go for that price. So is the Echo Flex a good deal? Yes. Is it unheard of? No, not really.What's more, Amazon still hasn't done much to address the concerns of privacy advocates, who are rightly concerned by the rising tide of individual consumers so readily planting cameras and far-field microphones in their homes. Such erosion of privacy, broadly applied, can chill free speech over time -- and Amazon has taken little more than perfunctory steps to address it.That said, the Flex isn't any more guilty of belonging to a tech giant with a spotty ethical record than a Nest Mini or Facebook Portal, let alone other Echo devices.For the Echo enthusiast, the Flex represents Amazon's latest, well, flex, in the smart home space. It's wallet-friendly, and despite my hesitancy to plant more microphones in my own home, I'm excited to see if Amazon keeps expanding the array of accessories that can turn the Echo Flex into any smart home gadget you want it to be.