I go to the webpage as required and see all my calls, but how do I download them all at once?
The calls are uploaded to the cloud services. You will have to access the web version of the cloud services to download the logs. You can't do this from within the application's interface. According to the developer's information, the software supports the following cloud services:
To find more about the software's features, use the following URL: https://play.google.com/store/apps/details?id=com.nll.acr&hl=en