It is html5 with some javascript. JSON is used but I am not using a library.
This loads the page with some default values in the form. The form is updated with the data that is currently in eeprom. If the form is changed the submit button is enabled, and when pressed it passes the arguments back to the ESP8266. They are then saved to eeprom.
Initially the values in eeprom will be messed up, but gets fixed with a first save. Hey, it was just for me.
http://192.168.100.109/ (your IP) will give a few links.
Set Relay On Off times is a link to a page on this website.
Show Relay State is a link to a page on this website.
Set Relay Name
Update firmware.
/relayName should be run, then /relayTimes to initialize the eeprom.
There are some diagnostic info available through the serial terminal. Options are listed in the Serial1.h file.
/relayName displays the content, but when the form is submitted I handle it with /saveTimes which reloads the page. I was using the /saveTimes before I figured out how to do the page update in /relayName. It should just stay on /relayName after the save. Something I have yet to do.
/relayName should also have loaded the contents of eeprom but I never got around to it. I only use it once so it wasn't important too me.