[Adverblessly]

Maybe related to being a SWE myself, but usually the first thing I do with any piece of software is go to the settings. If you do that with the Google Keyboard you'll see "Preferences -> Long press for symbols".

If you enable that, each key on the keyboard now shows an additional symbol you can get to by long press, for example, 'a' now also allows you to type '@'. If you try and long press for 'a' you'll suddenly see that accented versions of 'a' are also available. And that's the story of how I "naturally" discovered that same feature.