Android as a WiFi Relay

I know I can configure my Android phone using the hotspot to act as a WiFi to Mobile bridge – but what if I want to create a relay that is WiFi to Wifi. Before you ask why would I do that – it is because I sometimes find myself in the situation where I have to purchase a single device wifi plan and I wish to share it with another device. I would like to install on my phone but use my computer with the phone to the paid for plan…

is there an app for that?