Metric Chocolate Chip Cookies- enough said! This might be fun to do with an after-school science club, or if you have an oven available to you at school. (We do at EGMS).
Instantly converts length, area, volume, weight, temperature,fuel efficiency and power. Includes US customary and metric system. Helpful site for measurement unit.
Exactly as the title reads... a VERY simple graphing tool. If you are wanting to co-create a graph with students tracking some metric over time throughout weeks or months, then this might be a good tool. Functions are limited at this point, but sometimes simple is good.