Touch Fraction ℚ Android app
Touch Fraction: (Android interactive fraction)
About fractions, and the construction of the rational numbers.
Fractions: Interactive app.
Select equivalent fractions with the rational representation diagram.
(video as support material in the mirror link)
From my point of view, apps allow using the method of factorization into prime numbers. More clearly than the Euclidean algorithm.
Nummolt construction toys:
Touch Math apps.
This is a free app