Popup features:

Takes 3 word address input and converts to latitude, longitude
Takes latitude and longitude input and converts to 3 word address
Automatically opens tab showing location on maps when translating
Configure add-on behaviour

Additional features:

Automatic replacement of latitude, longitude to 3 word address in tabs - tested with google maps, and bing
Caches translation results, making it is faster since there is no need to ask API again

How to use the popup UI When converting from a 3 word address to coordinates, write the words separately in the 3 textboxes at the top, or the address (e.g "///beeline.scandalous.bruisers") in the orange textbox underneath. Tab or space bar can be used to select the next textbox. Press the enter key to translate. By default, a new tab on maps will open showing the location. Translation from coordinates to a 3 word address is performed similarly. Write the latitude and longitude in the bottom textbox (e.g "37.743413, 15.031307") and press enter. The add-on settings can be accessed by clicking the arrow at the very bottom of the popup. Uncheck the first two check boxes if you do not want a new tab to open with the location on a map when you use the popup to make a translation. Leave the last checkbox checked if you would like the add-on to automatically replace most instances of latitude, longitude in your tabs with a 3 word address. For example on google maps you will see "///beeline.scandalous.bruisers" instead of "37.743413, 15.031307"