Can we use an Android phone as a Wi-Fi repeater? Can we use an Android phone as a Wi-Fi repeater?

Imagine situation when you can access a weak Wi-Fi signal from a free hotspot (coffee shop) signal near window, but want to work in the middle of the room. Then we can put the phone on the window sill to spread the signal over the entire home.

Is it feasible?
No. To do this would broadly speaking require multiple Wifi interfaces (or specialized software) which is not readily available (or easily installable) on Android.

In general this is done on Linux using something like hostapd in master mode: I don't believe that is easily setup on any Android phone.