Although I'm not quit sure where the 'official' way to get this ID is located, I know that if you are viewing your app in HQ's app builder your URL is something like
thanks (and it would be good to know if there is an overview of these somewhere actually) but what I am looking for is how to get the app ID field into our Postgres database when I run the export tool, not to get the app id for a specific app.
The APP ID is only available if you are exporting forms. You can get it by using app_id as the Source Field. I've also updated the field reference document to list it.