Awful!
"Settings" does nothing.
"Menu" opens an non-existing domain.
The scanning steps vary between 0.5 and 1. So you can read at 1, 2, 2.5, 3, 4, 5, ... . Much to much points and not configurable.
The input of the contact points is with a granularity of 1 and not configurable. Much to coarse. The response of the programmer was that you can scale it yourself, so that 1/8 is 1. This would mean you also have to shift it. E,g, if your LCP is 8 3/8 you have to subtract 7 (lowest appearing LCP) and then multiply 1 3/8 by 8 giving 11. Wtf!
Contact points can be entered only in the range of 1 to 28.
The width is the sum of the left and right contact, i.e. LC 2 and RC 6 makes a width of 8 and LC 15 and RC 20 makes a width of 35. So if you do all the adjustments in your head like with the granularity, then you can calculate for e.g. a LCP of 8 3/8: 10 (highest appearing LCP) - 8 3/8 = 1 5/8 * 8 = 13.
The graph is a bar chart which is not easy to read.
It is not possible to save something or switch graphs. So you can just do one graph, throw it away and do the next one.
Because this app is over four years old I don't expect an update.