Get all DXA application data.

get-dxa-appdata.ps1

Import-Module Tridion-CoreService
$core = Get-TridionCoreServiceClient                              

Write-Host "global app data"
$data = $core.ReadAllApplicationData("")
[System.Text.Encoding]::Unicode.GetString($data.Data)
Write-Host

$itemIds = $core.GetSubjectIdsWithApplicationData("http://www.sdl.com/tridion/SemanticMapping/typeof")
$itemIds = $itemIds + $core.GetSubjectIdsWithApplicationData("http://www.sdl.com/tridion/SemanticMapping/vocabularies")

foreach ($itemId in $itemIds) {
    Write-Host "All app data for item $itemId"
    $data = $core.ReadAllApplicationData($itemId)
    Write-Host "application id " $data.ApplicationId
    [System.Text.Encoding]::Unicode.GetString($data.Data)
    Write-Host
}