Addigy doesn't support uploading entire directories at once--uploads must be individual files. This means that a .app file, which is technically a directory, must be first compressed into a single file before uploading into a Custom Software item within Addigy. For most .app installations, simply copying the directory into the /Applications folder will complete the installation.
Using Google Chrome.app as an example, here are simple instructions for compressing the .app into a tar.gz format.
cd "/Volumes/Google Chrome" tar -czvf ~/Desktop/chromeapp.tar.gz "Google Chrome.app"
This generates the file 'chromeapp.tar.gz'.
After uploading the 'chromeapp.tar.gz' to Custom Software in Addigy, you simply need to add this Installation Instruction to the Custom Software which extracts the .app to the /Applications folder on the device.
tar -zxf chromeapp.tar.gz -C /Applications/
Note: using the 'v' flag with the tar extraction it can delay the deployments of the policy and software enforcement.