This plugin gives you two-factor authentication using the Google Authenticator app for Android/iPhone/Blackberry. The two-factor authentication requirement can be enabled on a per-user basis. You could enable it for your administrator account, but log in as usual with less privileged accounts.
If You need to maintain your blog using an Android/iPhone app, or any other software using the XMLRPC interface, you can enable the App password feature in this plugin, but please note that enabling the App password feature will make your blog less secure.
Demo Download Plugin