I simply use Authy on my phone to store all 2 factor authentication codes. These codes can be protected using a master password so not just anyone can see them. There is also an "app" using Chromium browsers such as Google Chrome, Slimjet, etc where you can use it on your computer on any OS that uses such browsers (basically Windows, Linux, and Mac)
For phones, it supports Android and iOS. I've never had a problem with it and neither does any family members of mine that use it. I have about 6 codes on it so comes in handy instead of using text/call to get a code.
Since we're on the subject, you may not know but MalwareTips supports 2 step verification via app or email. Works great with Authy.
If I'm not mistaken, Google Authenticator (Android) and Microsoft Authenticator (Windows Phone) can do basically the same thing. Been awhile since I used them so not 100% on that. Being that Authy is not on Windows Phone, you'd have to use something else. Neither will work on a PC and I don't believe either have a master password to protect your codes from prying eyes.
