Outputs list of all Azure AD Apps along with their expiration date, display name, owner email, credentials (passwordcredentials or keycredentials), start date, key id and usage. Useful to know the apps that are expiring and take action (renew). Since Azure AD PowerShell is being deprecated in favor of Microsoft Graph PowerShell SDK, I created a …

Get-AzureADAppsInfo.ps1

# Requires Azure AD PowerShell Module
#Prompts user to login using Azure Credentials

Connect-AzureAD
$results = @()
Get-AzureADApplication -All $true | %{  
                             $app = $_

                             $owner = Get-AzureADApplicationOwner -ObjectId $_.ObjectID -Top 1

                             $app.PasswordCredentials | 
                                %{ 
                                    $results += [PSCustomObject] @{
                                            CredentialType = "PasswordCredentials"
                                            DisplayName = $app.DisplayName; 
                                            ExpiryDate = $_.EndDate;
                                            StartDate = $_.StartDate;
                                            KeyID = $_.KeyId;
                                            Type = 'NA';
                                            Usage = 'NA';
                                            Owners = $owner.UserPrincipalName;
                                        }
                                 } 
                                  
                             $app.KeyCredentials | 
                                %{ 
                                    $results += [PSCustomObject] @{
                                            CredentialType = "KeyCredentials"                                        
                                            DisplayName = $app.DisplayName; 
                                            ExpiryDate = $_.EndDate;
                                            StartDate = $_.StartDate;
                                            KeyID = $_.KeyId;
                                            Type = $_.Type;
                                            Usage = $_.Usage;
                                            Owners = $owner.UserPrincipalName;
                                        }
                                 }                            
                          }
$results | FT -AutoSize 

# Optionally export to a CSV file
#$results | Export-Csv -Path "AppsInventory.csv" -NoTypeInformation 

Another option that leverages the newer Az.Resources module is available here:
https://gist.github.com/GuyPaddock/c3e0fbb1e3724822c77e35a83160af52