BEST
Look up a network whose key is already shared
You give the network name you can see and the details that go with it, and the Instabridge WiFi password comes back with the details you need to join. No one at the counter has to be asked.

The network already shows in your list. Here you get the key that opens it.
You can see the network's name.
If not, step a little closer.
It wants a password you don't have.
If not, you are already online.
Works in the browser, nothing to install.
Read this first: only a network whose key someone has already shared can open. Nothing here guesses a private key.
Sorted by what actually gets you online, from the route worth trying first to the one that wastes an evening.
BEST
You give the network name you can see and the details that go with it, and the Instabridge WiFi password comes back with the details you need to join. No one at the counter has to be asked.
FINE
Both work. Both depend on someone being free to talk to you, or on having data left in the month.
AVOID
A key nobody shared stays closed. Anything that claims otherwise is selling you something else.
The name you typed, matched against the one broadcasting beside you. Two networks in a street often read almost the same.
Readable, in characters you can type with one thumb. Nothing to copy out of a screenshot of a screenshot.
Which entry on your phone to tap and what to paste. If the network wants a sign-in page after that, you are told so.
Do start from a network already shared by the people using it.
Do read the name letter by letter. A single swapped character sends you to the wrong network.
Don't try to force a home network, and don't pay for a tool that says it can.
Works in the browser, nothing to install.