Platform: Android, iOS
Security is super important when dealing with anything on the Internet. In addition to having a strong password, it's always smart to enable two-factor authentication if you are able to. Some providers will allow this through a text message sent to a designated phone number. Others rely on an authenticator app to provide a randomly generated pass code.
I already trust LastPass with my life essentially. So, trusting them as my two-factor authenticator was a no-brainer. Setup is easy. When enabling two-factor on an online account, a QR code will be presented. Line it up with the camera within the LastPass Authenticator app and the account will be added. Should that not be an option, you also have the choice to manually add an account via a code. The app can be secured with a PIN or fingerprint, helping to beef up security.
LastPass Authenticator is easy to use and it comes from a company I already trust. If you're serious about your security, definitely install this.