Neptune supports navigation between LATEX sources and PDF output. Click at any point in the source document to take you to the location in the PDF that corresponds to the cursor location in the text editor. See the screen shot below.
In the PDF window, you can see a red bullet blinking which corresponds to the cursor location in the source document. The red circle will remain in the PDF window for ten seconds and will disappear.
For navigating from PDF to source, you shall click on the desired line in the PDF, the corresponding line in the text editor window will be highlighted.