Have you tried using the  `SyncRoot` property on the `PlotModel` to synchronize the updates? Bound collections should not be changed while the plot is updating, I think.

Recent changes on the iOS implementation should also improve the alignment of the marker circles.

Cool, maybe we can add this to the examples? I'll have a look!

Sorry, the tracker is only implemented for WPF, Silverlight and Windows Forms. It would be great to have it on the other platforms too, but I am not sure about how to implement it...

Try to update the Xamarin.Forms component, the reference in the template seems to be not up to date. I just updated the documentation page about this.

I have started updating information about the TrackerFormatString, for LineSeries, see http://oxyplot.org/documentation/series/LineSeries

thanks for testing! Yes, smooth is interpolating the final transformed points and will not help here. In this case I think we need to interpolate before applying the polar axes transforms. I think there should be a similar problem for logarithmic axes. It could be handled by the LineSeries, but I think the problem is to find how many interpolated points are required... I think a workaround is to interpolate yourself before adding the points to the LineSeries. Add a ScatterSeries with the original points for the markers.

I think assuming the two collections are in sync is ok for the first iteration. Then the AreaSeries could be refactored in the next step.

Yes, please contribute:

1. add issue at github
2. fork
3. branch and do the coding
4. create pull request!

(added the image to your post)
Have you tried setting the "Smooth" property on the LineSeries to true?