* Camera -- Allows the app to take pictures and videos with this camera. This permission allows the app to use the camera at any time without your confirmation.
It's so you can use the app's barcode scanning capabilities to scan the barcodes of your rewards cards, or the number on your regular credit/debit card.
* Read your contacts -- Allows the app to read data about your contacts stored on your phone, including the frequency with which you've called, emailed, or communicated in other ways with specific individuals. This permission allows apps to save your contact data, and malicious apps may share contact data without your knowledge.
It's so you can send money to your friends, presumably sorted by who you talk to most frequently.
Frankly, for anyone who has used these apps, it should be pretty obvious what these permissions are for. Heck, the second permission should be obvious from just reading the description of the app, and the first permission is heavily implied by the fact that you can, in fact, add such cards from within the app.
Not having used the other 2 apps you mentioned, I can't really say why they need the permissions they need (my guess is the Starbucks app lets you call HQ if you have an issue or something). But they're in control of your money, and all you're concerned about is whether they _might_ make some phone calls you don't want them to make? They _might_ see that you're also running some other apps at the same time? Give me a break. There's nothing particularly nefarious about these permissions, and that Citeworld article is overblowing things as well. "I also wonder if Wallet's slow adoption rate has something to do with these intrusive permissions."? How about, "It's blocked by several major carriers to promote their own payment scheme, which somehow is accepted in even fewer places than the already rarely-accepted Google Wallet"?