The next step is to start your own experiments with ESP-01. For examples, the Arduino core for ESP8266 comes with plenty of interesting sketches to fiddle with! Note: As described earlier, when trying ...

A lot of people have used ESP8266 to add inexpensive WiFi connectivity to their projects, but [Oscar] decided to take it one step further and program an Arduino over WiFi with the ESP8266.

I followed [cnlohr’s] direct programming guide to write the binary using esptool. Both this method and the Arduino method are directly programming the EEPROM on the module.