SpiosJoop

Two small drawing-desk toys live side by side in SpiosJoop, and you switch between them from the strip along the bottom.

Loop Studio — the spirograph bench Pick how many teeth the outer ring has, how many the inner wheel has, then slide the pen closer to the rim or the centre. The curve is plotted from those three numbers as you change them, so the shape answers straight away. Underneath you get the petal count, how many turns the wheel takes before the pattern closes, the shared factor behind that, and how far the pen swings at its widest and tightest. Tap Coprime for teeth that share nothing and draw the busiest rosette.

Drop Run — the marble bench Build a track from ramps, drops, loops and flat runs, then set a push-off speed and where the catch cup sits. Tap Roll and a marble travels the whole thing. You read its speed leaving the last piece, the total height given up, the run time, and how far out the cup should sit to catch it. Any loop the marble is too slow to hold gets highlighted, so you know where to add height.

Both benches share four ink colours, centimetre or inch readings, and a saved list you can reopen or send.