Does anyone know how to display variant information on the genome browser that displays variant frequency as one would visualize in a lolliplot or manhattan plot?
I don't know if there's a way to display lolliplot using the genome browser, but do you mean something like this? If so, the Genome Graph is probably what you're looking for. The below example was a copy-and-paste version of allele frequencies for SF3B1 from ExAC to the browser using Genome Graph.
This looks nice actually, how exactly did you extract that information from ExAC?
For the example above, I got all the variants for SF3B1 via the export function from the web application, copied the 3 columns that contain chromosome, position, and allele frequencies, and pasted into Genome Graph. To automate the entire genome, I assume it's very doable by simply transforming the ExAC VCF into a tab-delimited file of 3 columns.