Screens & Cards
The primary presentation of Memento mobile edition is in a full screen — one which occupies the full app space on the device, but leaves the notification bar visible and accessible. This is how most modern Android apps are displayed.
Memento displays some "screens" as cards, which may or may not occupy only a portion of the screen, showing a bit of the underlying screen behind it. The user may choose by pressing a button for a card to occupy the entire screen or only a portion of it. Using a card gives the user a sense of the card as being modal, or temporary and subordinate to the outer screen. Cards make sense when the device display is large enough for the data to be readily visible, but may be inconvenient on smaller devices, hence the toggle button.