Here is an explanation of the most important permissions that Threema for Android requires:
Read/write contacts
Required for address book synchronization. If the synchronization is off, contact data is not accessed.
Camera
Required for contact verification via QR code and for the built-in camera app.
Microphone
Required for Threema calls and voice messages.
Location
Used for the “Send location” feature.
Accounts
Used for contact synchronization resp. integration into the account management of Android.
Modify or delete the contents of your USB storage
Required for reading and storing media files (images, videos, documents).
Make and manage phone calls
Required to reject incoming phone calls while a Threema call is ongoing.
