In 2009, I bought the first portable "HD" (digital) receiver at Best Buy. Best Buy's house brand is Insignia; this very small radio was given the model number NS-HD01. It has since been supplemented by the NS-HD02, which I don't have (and don't plan to get). The HD01 is a basic but competent unit. Its retail price was $50, but it often was available at a discount. Best Buy did not pitch it as a radio, but as a "digital player".
It's FM-only, with a basic set of controls and only eight presets. But the volume control is clever: flip it up or down to change the volume, or push it in to mute temporarily. All tuning is done either with presets or with the up or down buttons.
It must be a DSP unit, similar to the Tecsuns and the Degens that I have. I say this in part because it can decode digital signals using the HD system employed in the United States, and also because its performance is similar to those other DSP radios. HD signals require a more sensitive tuner than analog signals, but the benefit of the more sensitive tuner isn't limited to the digital signal. This radio is free from overload and self-generated interference. It isn't as sensitive as the Tecsun or Degen radios. That may be due to its dependence upon use of a headphone cord as an antenna. That's a common practice with small units such as this one, but it makes it difficult to create an antenna that's at the right length to pick up FM signals.
There are no tone controls, bass boost, or so on.
One nice feature is that it shows either the HD text display or, for an analog signal, the RDS display for the station (a separate type of slow-speed data stream that shows basic information).The display above is on KFRC-FM, which simulcasts KCBS(AM) in San Francisco.
Whether HD radio has a long-term future is a controversial question, and I'm not going to take a stand on it here. I will say that this unit is a competent performer, though not likely to be long-lived: it runs off a sealed rechargeable battery, which can be charged with any USB charger. When the battery goes, the radio won't be usable any more. No doubt this was done to keep the radio very small. But you're not likely to see any of these on eBay 20 or 30 years from now.