.app
文件类型1：Symbian OS Application
文件说明：
Software program written for the Symbian OS, an operating system for mobile phones and smartphones; comprises a Symbian application together with a .RSC resource file; can be compiled using a Symbian OS software development kit (SDK).The Symbian OS is used by phones from Nokia, Sony Ericsson, Samsung, and FOMA.
打开.app文件
Mac OS
Windows
Nokia Carbide.c++Nokia WRT plug-ins
Nokia Symbian rcomp
Runs on supported cell phones
Linux
其它内容
.app
文件类型2：FoxPro Generated Application
文件说明：
Application used by FoxPro to automate procedures (i.e. creating new label sizes, transforming data values, analyzing code, etc); may be included with FoxPro or custom built by the user from a project (.PJX) file using the BUILD APP command打开.app文件
Mac OS
Windows
Microsoft Visual FoxProLinux
.app
文件类型3：Mac OS X Application
文件说明：
Application program (or executable file) that runs under Mac OS X; runs when double-clicked; similar to a .EXE file in Windows.Because APP files are Mac OS packages, you can right-click (or control-click) an application and select Show Package Contents to view the files contained in the package; these include Resources used by the application, property list (.PLIST) files, frameworks, plugins, icons, and other files.
In Windows and Linux systems, it may be possible to view the contents of a Mac OS X application as if it were a folder; a decompression program like WinRAR may also be able to extract files from a Mac OS X application on other operating systems.
NOTE:
Files within an application package should not be edited or moved, since changes may prevent the program from running correctly.打开.app文件
Mac OS
Runs itselfWindows
Linux
来源：. app文件