SwitchIoT 4CH is a tools will guide you to make a DIY Sonoff 4CH smart switch based ESP8266 chip (Wemos). Using this app for directly uploading firmware to ESP8266 then setup it, no need computer/laptop for configuration.
Make an IoT device is as easy as uploading firmware without the need for registers/login and server configurations.

Features:
- Turn on/off 4 home appliances remotely
- Remote ON/OFF–Turn electrical devices on/off from anywhere
- Independent control–Control each gang separately
- Sync Status–Real-time device status provided to App
- Share Control–Control your smart home together with your family
- Timing–Set scheduled/countdown/loop timers to turn on/off at specified time
- Uploading firmware

Hardware Requirement:
- Wemos (ESP8266)
- Relay module 4 chanel
- Tact switch 6x6x12mm (Button)
- PCB prototype double layer 3x7mm
- LED 3mm
- Wire 30AWG

Follow this tutorial to make a DIY Sonoff smart switch:
https://www.instructables.com/id/Make-a-Cheapest-DIY-Sonoff-4CH/