Review on 📡 Makerfocus ESP8266 ESP-01S WiFi Serial Transceiver Module (4pcs) with 1MB Flash for Arduino - Enhanced Connectivity and Storage by Donna Jones

High quality circuit boards, work great. Reasonable price for fast shipping from USA. Thanks very much! I use it as a WiFi button. Press the button for a second and a message will be sent to my web server. From there I can do anything (enable one or more smart plugins, send a tweet, send an email, run a script - or all of the above). Total price with case and batteries is about $10. They are a lot of fun to work with and easy to program with the Arduino software development tool. Edit: I ordered a few more. I built a garage door sensor (so we know if it's open or closed). I'm adding them to an old motion detector so it notifies about wifi. They are addicting. Once started I want to add WiFi/Smarts to everything.