Some apps require a little extra work to make things play nice with the Superbook. Some just don't work.
See below for details.
In the settings for Dashlane, there is an option to "Allow Screenshots." With this turned on, the app will also use the Superbook screen.
This doesn't work at present.This is due to a current hardware limitation, which was discussed in Update #39 on Kickstarter. A software workaround will be looked at in future following completion of delivery.