On a Windows laptop you can indeed just use file explorer (smb) to connect to other Windows hosts and view their file shares.
You may need to enter the remote IPs directly. If you are passing a dns search domain to clients and pSense as a DNS server they may be able to resolve LAN side hostnames if pfSense is a the DHCP server there.
The hosts you are connecting to need to allow smb connections from the OpenVPN tunnel subnet of course.
Anything you can do from the Android phone locally on WIFI should also work over OpenVPN.
I don't know what you are trying there. I'm not sure I've ever tried to access smb fileshares on a phone. There may well be an app for that.