Apps require permissions to operate smoothly. The permissions you give allow the local app installed on your phone access to some resources on your phone. These resources are accessed by the Haystack app installed on your device, but the data isn't sent to our servers unless absolutely necessary.
Permissions (in more detail):
Calendar - to enable a feature we're testing that will allow you to share your card with the people you're meeting with in a single tap (this would not edit or delete calendar events, and the data does not get sent to our servers)
Contacts – enables you to share any of your contacts with other people using Haystack, as well as sync your Haystack contacts to your phone's contacts
Location – so we can add a location stamp for each of your business card scans (we do send this data to our servers so you will be able to search for it later)
Photos/media/files/storage/SD – enables the app to import an image from your gallery when you want to do so (and make your business card look awesome)
Camera – so you can scan business cards you receive from others