Earlier this year, I had wondered whether it was feasible to implement the Karma attack on a low-powered device, such as the ESP8266. It turns out this was quite simple, and you can now find a template for this on Github here.
The code is not a complete WiFi pineapple on an ESP – by design, this only implements part of the attack, it is up to the user to provide the “rogue AP host” and network back-end (but on the low-power theme, you might be able to forge this via another ESP8266). No preferred network list functionality is provided here either, but this isn’t too difficult to implement – the ESP is fairly generous in terms of resources for this.
If you want to play around this, the following video is well worth watching. The concepts discussed here are all relevant, no matter the hardware platform (though against modern devices, they have varying degrees of effectiveness – the most effective seems to be preferred network list based trickery, or good old fashioned fake beacons).