Two step verification + app specific password works fine. When you enable you'll be signed out of every Google session you have through any interface.
Since I'm a big Google user and have to use a handful of 3rd party apps on the iPad I went ahead and made an iPad specific password, while I also enabled two step verification.
For the mail app on iPad I just put in my new password when it said the old one was wrong, for Google voice on iPad it redirected me to the browser to enter in the verification code it texted my phone.