Take this example: http://dx.doi.org/10.1017/jfm.2015.335 It is a random (recent) paper from journal of Fluid Mechanics.It should be on open-access at this moment.
If you open it with acrobat reader (currently on Windows, cannot say about Linux readers), when you hover with the mouse over a reference to a figure or a citation a "pop-up" appear with the figure or the citation itself.
How can I achieve the same effect?
NO MWE because it is not related to a specific problem, but more a general question about how to do it.
Anyway, example are welcome!