As you might know EAGLE projects are separated in two files, a layout (.brd) and schematics (.sch) files. Copper needs both files, but it is possible to inspect layouts without schematics. Inspecting schematics only is currently not supported.
Copper comes with a built in, simple web browser.
Start the web browser
If you like, you can use Safari to browse the web. But the most efficient workflow is to use the built in browser. In document library tap on the + icon.
There are a few services that you can choose from. Dropbox is special, as it uses a built in Dropbox client that is more comfortable to use then the web.
Github and Aisler start the web browser and point it to the corresponding homepage which saves you some typing if you typically download files from these services.
Download a file
As usual, download a file by tapping on a link or button. Copper will catch downloads and handle them instead of pointing the browser to that location.
In this example we opened arduino.cc URL and navigated to the Arduino Uno R3 page. At the bottom of the page is the download button for the EAGLE files. It's a ZIP file.
If the file you downloaded is a .brd or .sch file, Copper will immediately start downloading the file and will bring you back to the library. If you selected to download a .brd file, Copper will search for a .sch file at the same location, as EAGLE files mostly come in pairs of a layout and schematics file.
If you download a ZIP file, Copper will download that file and examine its content. You will then be presented with a screen that let's you choose which files Copper found in the ZIP should be imported.
Once you have made your selection you are brought back to the library screen where the new files should be presented. It might take a few seconds until the thumbnail image is rendered.