Do you have weak spots in your home WiFi? So did I and I decided to fix it on a budget. Here is the how to set up OpenWRT as an AccessPoint repeating your WiFi SSID (repeater mode) using the LuCi web interface.
For the demo we use a TP-Link TL-WR1043N/ND v2 which has OpenWRT (Chaos Calmer 15.05 with LuCi 15.05) which is factory reset.
I use a mac for the demo, because it was the device giving the most WiFi issues in the house.The default language of the mac is Dutch but the buttons you need to click will be in the same place ;)
On my Android phone I use the app Wifi Analyzer to pick the best WiFi frequencies for the router and the various access points.