You can add multiple Google accounts on your Android device. However, it considers the first account you sign in with as the default and uses it to sign you in across various Google apps and services.

You can change your email signature on an Android device in just a few steps on the standard Email app or the Gmail app.

To switch between inboxes, tap the Profile icon in the upper-right corner and choose an email address. Another option is to install the provider's app. Outlook and Yahoo have their own apps. This ...