A circle plot.

A dot plot.

A presentation plot with shifting each data curve depending on the z-axis value.

A 3D plot with circles using the same data above.

A density plot of bicolor.

A density plot of rainbow color.

A 3D plot with rainbow color.

An image of editing data points.

yoshinoGRAPH is a scientific graph software for data analysis and presentation. You can make 2D and 3D graphs quickly from data files in text format. This software is tiny but includes many basic functions to analyze/edit data as well as rather advanced ones.
Features:

plot styles: scatter charts, density and 3D plots with and without lines

double Y-axis and shift in Y direction are available in 2D graph

easy to change scales among linear, log and inverse

polynomial and 3rd spline fits

manual fit of two independent lines to a data curve

easy to remove scattered/noisy data

easy to convert data; quick sort, smoothing, making tables and so on

to draw a math function on 2D graph using an expression

to copy a graph as metafile and bitmap formats to paste it on a presentation software

easy to read many data files saved in different folders