In Genius Scan+ v2.3 we introduced AirPrint support.

AirPrint is an Apple technology which allows you to print wirelessly. To access AirPrint in Genius Scan, you just need to use the export menu and choose the Print option.

AirPrint is available in the export menu

You can then choose a printer and some printing options and here is your homemade photocopy:

AirPrint UI

Everyone doesn't have an AirPrint-compatible printer though. But this isn't a blocker issue. The trick is to use your Wifi-enabled computer as an bridge to your printer by installing a software similar to AirPrint Activator. You will then be able to see any printer recognized by your computer as an AirPrint printer.

None of these printers are AirPrint compatible to begin
with. However, by installing AirPrint activator on your
 computer, this makes them magically compatible.

AirPrint is supported in Genius Scan+ ($2.99). You can also give a try at the free Genius Scan and update to Genius Scan+ as an in-app purchase.