Hi,
I have designed many ESP based board before. And most of them was my recent projects. So, I'm familiar with ESP32 design guide and component used for it. For firmware, we can use Arduino environment and using MQTT as protocol to interact with app.
I have 8 years experience on PCB design, and IoT boards was my mostly recent projects. I know several design issue needed to be considered on IoT board design.
I will use KICAD for this project, and using 2 layer board is enough for me.
Let's discuss the details over chat.