Little Scientists

The five toys

• Wiggle World. A jar of particles and a fire-and-ice dial. Cold particles lock into a grid, warm ones slide about, hot ones fly. The dial shows real temperatures: ice melts at 0°, water boils at 100°, iron needs 1538°. The magnifying glass swaps between the particles and what you'd actually see.
• Partner Swap. Molecules are atoms holding hands. Flick them together, or turn up the heat, and they swap partners: hydrogen and oxygen make water, gas burns into carbon dioxide, baking soda and vinegar fizz. A tray counts every atom, and the numbers never change.
• Atom Builder. Drag in protons, neutrons and electrons. The number of protons decides which element it is, shown on a card with its number and symbol. Too many neutrons and it wobbles. A full outer ring makes it spin with joy.
• Element Zoo. The first four rows of the periodic table as a building. Tap any flat and that element does its trick: helium floats, neon glows, sodium fizzes, iron jumps to a magnet, gallium melts in your hand, carbon becomes a diamond.
• Sink or Float. A tub of water and a shelf of things. Guess first, then drop it in. The magnifying glass shows how tightly packed each thing is, with its number next to water's 1. The clay ball sinks, but tap it into a boat and it floats.

Made for small hands

• No words to read. Letters and numbers appear only where a child can recognise them: element symbols, counts and temperatures.
• Big targets, drag and tap only, and something happens the instant you touch anything.
• Now and then a toy asks for a guess with two pictures. A surprise gets a delighted "whoa", never a buzzer.
• A grown-ups' sheet, behind a two-second hold, explains the science behind each toy and suggests something to try at home.

Installing

1. Tap Download for Android on your phone or tablet.
2. Open the downloaded littlescientists.apk.
3. If prompted, allow your browser to install unknown apps, then tap Install.
4. Open it and hand it over.

No scores, and nothing to protect

• No streaks, stars, timers or levels to finish. The only thing it remembers is which elements have been built, so they sparkle in the zoo.
• No accounts, no ads, no analytics. Nothing leaves the device.
• Every toy works with no connection at all.