Ocean charts are too small a scale to plot sights on, so navigators use a universal plotting sheet: a blank grid you label for your own latitude. The parallels are printed; you draw the meridians, closer together the further you are from the equator.

Parallels are a fixed distance apart. Draw a line at your latitude from the center of the rose; a meridian dropped from where it meets the circle is one degree of longitude east of the center.

Mid-latitude of the sheet: 40°
1° of longitude, as a share of 1° of latitude: cos 40° = 0.77
So 1° of longitude here is: 46.0 nm

Measure distances on the latitude scale (the side of the sheet), never on the longitude scale. Near the equator the sheet is nearly square; at 60° the meridians are half as far apart.

Latitude: 40°

Label the middle parallel with the whole degree of latitude nearest the DR; the parallels above and below are one degree more and less.
Draw a line from the center of the compass rose at your latitude above the horizontal.
Where it meets the rose, draw a meridian. Its distance from the center meridian is one degree of longitude; repeat outward.
Label the meridians: in west longitude the numbers increase to the left.

The app's practice sheets are drawn this way for the latitude of each problem.

Making a plotting sheet