The source code for Dimension Explorer, an add-in for exploring time-aware and multidimensional data, is now available for download. Version 1.11 is a minor update from version 1.1 and is built specifically for ArcMap 10.4. This version features tighter integration with the ArcMap Table of Contents window - as layers are added, removed or changed, the contents of the layer selection list in the Settings window are updated accordingly.
Update - I've had reports that the layer selection list is not getting updated consistently as layers are added, removed, or had their properties updated in the map document. Until this issue is resolved, I recommend users of ArcMap 10.3.1 and 10.4 use version 1.1 of Dimension Explorer instead. I apologize for any inconvenience this may have caused.
Dimension Explorer 1.11 (addin and documentation)
Dimension Explorer 1.11 (source code and documentation)
Dimension Explorer 1.1 (original blog post)