This app can help you to balance a chemical equation.

In this app, the chemical equation will be displayed at the top of the screen, you can click the checkbox to open a Molecular formula list and select the reagents and products. There are 4 reagents and 4 products at most. You can move the thumb of slider to change the factors of each molecular formula in the equation. When you have written a complete equation, you can click Check button to check your answer. If your answer is right, a right mark will be shown, and if your answer is wrong, a cross sign will be shown. At this moment, you can press down the hint button to look at the right answer. You can click the reset button to write a new chemical equation.

This app won the first place of People's Choice award in 2021 MIT App Inventor Appathon.