I would recommend simply preventing the app webpage from allowing cookies.
To the right of the browser address field, click the three horizontal lines, and then click Settings.
Click Show Advanced Settings.
Under Privacy, click Content settings.
Under Cookies, choose from the following options:
Allow local data to be set
Keep local data only until I quit my browser
Block sites from setting any data
Block third-party cookies and site data
The one you want is probably "Keep local data until I quit my browser."