Electronics Circuit

is a good application for school, college and work. If you are a student, it will help you learn a lot.
In other times you had to buy it manually or buy special calculators, today with only having a smart device, you can have these tools that help improve the learning of these topics.

Serves for many topics in this area, approximately 79 among them I can mention:

1. Ideal diode
2. Semiconductor materials- Resistivity.
3. Semiconductor materials Ge and Si
4. Energy levels
5. Extrinsic materials n-Type
6. Extrinsic materials p-Type
7. Electron versus Hole Flow
8. Majority and Minority Carriers
   Source

In the information of the app you can see more in what you can do.