Review on Goblown USB SD Card Reader and OTG Adapter for PC, Laptop, and Smart Phones - Micro SD Card Reader/USB 2.0 Cardreader for TF, SD, Microsd, SDXC, SDHC, MMC, RS-MMC, Micro SDXC, Micro SDHC, UHS-I Camera Reader by Robert Olguin

This has to be one of the cheapest USB devices I've used but for $7 I'm not complaining. It is easily recognized by my computer and easily starts transferring files with no hiccups. The only negative thing to mention is the transfer speed: I couldn't get more than 16MB/s on a full-size SD card, and there's no more than 11MB/s on a micro SD card, so it definitely doesn't look like a full-speed 2.0 device, but if you're looking for something this cheap then it probably isn't a deal breaker. If you want something as cheap as possible that can read SD and Micro SD cards on your computer/older Android phone then this will do the job. If you regularly transfer files and want to do it faster, there are many better and more expensive USB card readers out there.