Learn Spanish (Latin America): Aun mirando el navegador, sigo sin entender esta calle. - Even looking at the GPS, I still don't understand this street.

When it means "even," aun is written without an accent mark. When it means "still" (as a synonym for todavía), it is written with an accent: aún. Here, Aun mirando means "Even looking," which introduces a concessive clause (a phrase that shows an unexpected result).

Could I use aunque instead of aun + gerund here?

Yes! You could say Aunque estoy mirando el navegador or Aunque miro el navegador. Using aun + gerund (Aun mirando) is a concise and natural way to say "Even doing [something]" in Spanish. It works perfectly here because the same person is doing both the looking and the not understanding.

How does sigo sin entender mean "I still don't understand"?

The verb seguir literally means "to follow" or "to continue." The formula seguir sin followed by an infinitive (like entender) is the standard way in Spanish to express that you continue not doing something. In English, we usually translate this as "to still not [do something]."

Doesn't navegador usually mean an internet web browser?

It does, but it is also the standard everyday word for a GPS device or a mapping app on your smartphone.