IMHO the Authy app is nicer than Google Authenticator.
https://play.google.com/store/apps/details?id=com.authy.auth...
https://play.google.com/store/apps/details?id=com.authy.auth...
Device & app history
read sensitive log data
Identity
find accounts on the device
Camera/Microphone
take pictures and videos
Wi-Fi connection information
view Wi-Fi connections
Other
receive data from Internet
access Bluetooth settings
pair with Bluetooth devices
full network access
view network connections
control vibration
prevent device from sleeping
send sticky broadcast
Identity
find accounts on the device
Other
control vibration
full network access
use accounts on the device
create accounts and set passwords
close other apps
Camera/Photo for QR code-based 2FA, Bluetooth permissions and Internet Data to handle local connection to trusted machines and callbacks from sites like Coinbase (when I log into coinbase, I get a handy 2fa notification from authy that leads me right to the code)
Log data is the most questionable, but it really makes debugging so much easier when you can see what's going on, and is a pattern/permission they share with Evernote, foursquare, fring, Netflix, Rdio, Dolphin Browser, AccuWeather.com, Hotmail, doubleTwist Player, MOG, Handcent SMS, Bump, TweetCaster, etc.
It does one thing, and does it well. It doesn't keep trying to get me to use a service where I hand over all my 2FA secrets to some company, and whats more the developer responds pretty quickly when there are support issues (e.g. some QR codes are weird sizes and there was a trick pre-iOS8 to make them scan) or even bugs.