How perfectly can you draw a circle by hand? Trace one smooth loop around the dot with your finger and get scored from 0 to 100% on how round it is. Beat your best.
Put your finger on the screen and draw a single circle around the centre dot in one smooth motion, then lift off.
The moment you release, your loop is measured against a perfect circle: the closer every point sits to the same distance from the centre, the higher your percentage. A flawless ring scores near 100%; an egg shape or a wobbly one scores lower.
Draw big — tiny circles and half-finished arcs don't count. Your stroke has to close back near where it started to be judged.
Each attempt shows your score and traces the ideal circle over your line so you can see where you drifted. Save your best percentage to the Hall of Fame.
Speed beats caution. A circle drawn in one confident, quick sweep is almost always rounder than one you inch around slowly, because slow hands introduce tiny corrections that show up as bumps. Commit to the motion and let your arm, not your fingertip, carry the arc.
Pivot from a fixed point. The roundest hand-drawn circles come from keeping your wrist or elbow planted and swinging through, rather than sliding your whole hand across the glass. Anchor a joint, treat it as the centre, and your finger naturally traces a constant radius.
Size is your friend, within reason. A larger circle gives the scorer more room to reward smoothness, and small deviations matter less against a big radius — but go so large that you run out of screen and the top or bottom will flatten. Aim for a loop that comfortably fills the drawing area.
Study the reference ring after each try. When your score appears, the perfect circle is drawn over your stroke; notice whether you consistently bulge on one side or flatten right at the start, and fix that one specific habit on the next attempt instead of just trying again blindly.