I use an Apple Airport Express WiFi basestation in Wireless Bridge mode for development as it means I can just connect an Ethernet cable and whatever board I'm playing with gets an IP address without having to muck about with WiFi drivers or configuring a connection. The last one I purchased (admittedly a couple of years ago) was about $20. It's not a blistering fast wireless connection, but it's "fast enough" for streaming moderate bitrate content for LE box/board testing and means I don't need to run a cable through three walls.
TL/DR; any bridge device, or any router that can be configured as a bridge, is what you need.