Android device to use as hotspot that can also connects to another wifi

Hi everyone,

This is something of a convoluted situation, so please bear with me.

I normally connect to the internet where I am through a WiFi that requires login through a captive portal (the ones you need to log-in through your browser that are common in bars and university grounds and such. The one I use is BT WiFi from the UK, in case you're wondering).

Doing so with android devices is fairly comfortable, as there's an official app for the network that while a bit clunky, reconnects you and logs you in automatically on the wifi every time it your session expires.

However, this works just for the device with the app itself. What I've been doing is connecting my android phone to the network with the app, activating tethering and then using it as a makeshift usb modem.

While this works, it only works with certain devices. I was looking forward for a more "unifying" solution so to speak, so I was wondering if there's any android devices out there that could:

A) Connect to the WiFi network and through the official app, automate reconnections when the session expires and
B) At the same time work as a WiFi hotspot, tethering other devices through it via wifi, not direct connection.

Is there such a thing or similar approach?

Thank you!