I've been improving the timeline-slider in my visual programming system code-flow-canvas.. you can try it out here : demo.codeflowcanvas.io (best experience is on desktop since the mobile and touch responsiveness is still lacking).

Additionally the state-machine node now also shows its transitions when executing a flow or using the timeline slider.

Also some the nodes that are used to visualize data have been connected to the flow-execution history. Some changes were needed in keeping track of state and updating nodes visually when using the timeline slider.

In this video I show some of the examples together with the timeline slider here: youtu.be/ElNTPWdWfFQ