I am using RaceChrono Pro for Android with a VBOX Sport GPS logger with an external antenna. After an update last autumn in 2017 (I don't remember which one exactly was and I couldn't find anything related in the Changelogs of the last versions), I've realised that the analysis graphs are now reporting the raw acceleration data as logged from the GPS. In the previous versions, the analysis graphs seemed to plot calculated values from the GPS position, which led to smoother curves with no crazy spikes, especially in noisy environments. Although a GPS with an external antenna can cope well with a noisy environment in keeping an accurate position, and VBOX is really good at that, it still suffers with the acceleration data in such environments. It would be great if you could add an option in the analysis panel to show the calculated acceleration values from the GPS position data as before.
Another suggestion I'd like to make, again related to the above, is to allow users to disable the autoscaling of the axes and use custom min/max values instead. Also, with that update I've mentioned before, another good feature "disappeared": when you were holding down your finger a bit on the analysis graph, the graph was automatically scaled to match the data shown within the visible frame. Currently, this happens instantly and immediately reverts to the global scaling for the graph, so you cannot focus on a specific area of the graph anymore...
Keep up with the good work!