https://play.google.com/store/apps/details?id=com.bluino.esploader A tool runs on Android platform,

A tool runs on Android platform, makes it easy to upload binary file (result of compiled Arduino IDE) to any ESP8266 development board via USB (OTG).

Does it work with ESP32 too, or only ESP8266 for now?

Only esp8266

Great!

Only arduino firmware?

And spiffs?