Will I be able to connect other microcontrollers like esp32, Arduino nano 33 IoT, stm32 etc with the bolt IoT app? If not, is there any other similar platforms available?
Yes with Arduino Uno, I am making one project with it. It works fine. I guess others also might work.
The above link helps you to get overview of Arduino Uno with bolt module. But both bolt module and Arduino should be connected to work.
ESP32 and Bolt device does the same work. You can use Arduino Nano with the Bolt Module for similar portable compatibility.
No, you cannot control other microcontrollers using the Bolt App. It is designed to view the uploaded code in the products section. And only Bolt modules can be connected there.
You can use Blynk IoT app to control IoT devices like ESP322, ESP8266, Node MCU, Ai Thinker modules etc.
Or you can make your own apps and connect with it on the local server.
Other than this, you can use Cloud Platforms like Google IoT Core, AWS IoT to visualize, store and control your module. The cloud shell scripting will enable you to do all this from one single platform.