This app has also a FREE Version with the same name. Search it on the store or visit https://metatransapps.com
The game demonstrates how the gravity force is working between the space objects.
Background from physics:
1. The gravity force is getting bigger when the distance between the objects is decreasing, and the force is getting smaller when the distance is increasing.
2. The gravity force also depends on the mass of the space objects, so the objects with bigger mass create stronger gravity fields.

Playing instructions:
When you touch the screen with a finger, the touch point immediately becomes an object with mass.
It has much bigger mass than the freely flying asteroids and is visualized as a black hole.
The goal of each level is to collect 137 flying asteroids into the screen, using the gravity force of your finger.
During the play, you keep or move your finger on the screen and observe how the gravity force is moving the objects.
If you move your finger to cross the orbit of an asteroid you could see the effect of gravity force, which changes the direction and the speed of the asteroid.
After each level the asteroids become faster and the space they are flying in is increasing.

Features:
1. Amazing graphical assets (asteroids, black holes and backgrounds) in 4 different color themes (purple, pink, green, red).
2. Increasing difficulties.
3. Supports different color palettes for different tastes.

Permissions:
The free version of the app uses ACCESS_NETWORK_STATE and INTERNET permissions, because it shows ads.

Your feedback and/or review is more than welcome.

https://metatransapps.com/gravity-force-finger-137-cross-the-orbits/