CYDI is a free drawing accuracy game that runs straight in your browser. Each round shows you a target shape for a few seconds, then clears the canvas: you redraw it freehand, by eye, with a mouse, trackpad or finger.
The moment you finish, your attempt is compared against the target and scored out of 100 - shape match, coverage, smoothness and scale all count towards the total and the star rating. Your drawing is shown on top of the target too, so it is obvious where the line drifted, and you can retry the same shape as often as you like to push your best score higher.
There is a large library of shapes to work through, grouped into categories like geometric shapes, symbols, letters, nature, food and sports, plus a new Daily Challenge every day. Nothing to install and no account to create - your progress and best scores are stored locally in your browser. An Android version is available if you would rather play in an app.