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.

When browsing the web with Google Chrome, Google marks one account as your default in your web browser. This works similarly ...

Setting up Yahoo email on your Android device is a similar process. You can add your Yahoo Mail account through Yahoo's app or Google's. Follow these steps to add a Yahoo Mail account to the Gmail app ...