Application connects with two remote servers using REST API. On the sign-in screen you need to provide the login and password or pick the demo-mode. Next screen provides an account info. If Auth token was outdated, it wil refresh automatically. If the internet connection was lost, user will see a toast. On bottom navigation you can to choose the another tab with quotes list. You can pick the start and end date/time periods and pick the need currency pairs - the App will provide information in cards on the list. If you need to logout, you can pick the "logout" icon on the right corner of toolbar.