This app does not (and cannot) communicate in any way with any device other than your own. The only files it reads or writes are its own database file and files that you opt to import or export beers from.
When you contact me using the "email developer" option, the app includes in the email details of the type of device you are using along with information about its screen resolution, as well as details of your app's saved settings. This is to help me diagnose any problem you may be reporting, as there are a huge number of configuration combinations and a bug you encounter may be unique to your setup. All of the information which is sent is visible to you as you compose your email.
Explanation of permissions requested by the app
read/write USB storage. Needed so that the database can be exported and imported from your SD card.
network access. Used purely during the first run of the app so that you can import the list of breweries from the Beermad website if you so wish.
location. This is used purely to record the GPS co-ordinates of pubs in which you sample beers so that subsequently the "where sampled" box can be automatically filled in. This can be disabled in the beer settings view if you don't want to allow it. To minimise battery-drain, GPS is only enabled by the app for as long as it takes to get a fix and identify the nearest known pub.