| apa | RSView Application Manager Archive |
| apalbum | Apple Aperture Album |
| apb | Alphacam Punch VB Macro |
| apb | LonWorks Binary Neuron Application Image File |
| apd | Adobe PageMaker Printer Description |
| apdb | Apple Photos Database |
| apdisk | Mac OS X Disk Information File |
| apertureedit | Apple Aperture Edit Data |
| apf | Adobe Profile Format File |
| apf | ATO Profile Data |
| apf | Autodesk Showcase Packet File |
| apfacename | Apple iPhoto Face Data |
| apfolder | Apple Photos Folder Data |
| apg | PowerADA APG File |
| aph | Ability Photoalbum Album Data |
| api | Adobe Photoshop Ink Colors Setup |
| apin | Adobe InDesign Filter |
| apkg | Anki Exported Flashcard Deck |
| aplibrary | Apple Aperture Library |
| aplmodel | iCal Application Layout Data |
| apm | Alphacam Punch Param Macro |
| apmaster | Apple Photos Master Data |
| apmx64 | Rohitab API Monitor x64 Capture Data |
| apmx86 | Rohitab API Monitor Capture Data |
| app | Alphacam Punch Post Data |
| app | ThecusOS Application |
| app | Wii U Game Data |
| appcache | HTML5 Application Cache |
| appcontent-ms | Microsoft Windows Application Content |
| appdata | VMware Workstation appData Data |
