Best method/plugin to store a secure token in an Ionic application

We are currently building an app that needs to store an authentication token securely for remaining REST API calls.

The initial (session) token is generated remotely after authenticating a user via username and password and is then passed to the app to be stored in a secure manner. Further API calls from the app pass the token to the remote API to be used to determine the current validity of the session.

There is currently a Cordova plugin called SecureStorage for both iOS and Android however the minimum version of the Android SDK the plugin supports is 19.

Due to the intended audience of this app, we need to support Android 4.1 and above so this plugin would not be acceptable. Something similar to this plugin but support for older versions of Android would be great but I am struggling to find one.

What kind of solutions/ideas have others used for purposes similar to this?