Newbie BLE Extension functions & IOS compatible?

Hello to everyone.

I'm new in developing app on mobiles.
1- I tried another similar app builder spending a lot of time and discovering that some functions are not properly working.
Therefore before starting I would like to consult specialists / experts of MIT APP inventor.

2- The project is quite simple
I have 3 devices (EPS 32) and 3 phones (1 AndROID - 2 Iphones / IOS).
In regular device A "belongs to" phone A B device to phone B etc...
However sometimes, Phone A need to use / connect to device B or C.

3- Connection is Bluetooth BLE with both UUIDs (Service + Characteristics specific for each device)
4- The project is to turn on-off a relay and get the script back from the device.

Therefore before I start the questions are:
A- Are the following "functions / operations" working on both platforms (ANDROID & .....IOS)?B- Listing the available bluetooth devices
C- Connecting to them (one at a time) BLE
D- Receiving data / info from the device Esp (text... for ex. "traditional Hello World")
E- Sending data (Text) to device.

Thanks in advance for your comments