What do you usually do when you fall behind in your maths class? Just pray you manage to pass at the end of the year? Yeah, that's what people usually do. 

Source: EducationNews

Not this teenager, though. 

Amit Kalra, a 16-year-old student from California, was falling behind in his mathematics class, not because he couldn't handle it, but because he had to change schools twice during his freshman year. 

Source: BusinessInsider

Talking to Business Insider, Kalra said, 

I started struggling, I was on my own. I didn’t know anyone in class.

So what did he do? He decided to build a mobile application to do all his homework for him. 

Kalra built an iOS app, 6284 Calc, that helped him catch up with the other students in the class. What it does is take all the guess work out of simple problems in algebra, geometry, and calculus. All that a user has to do is input values of all the variables and the app does all the calculations for them. And if you are ready to pay a small one-time fee of $1.99, it will also show you all the steps involved in the calculation. According to Kalra, this app will help students who end up not doing their homework at all. 

Source: Insider

The app has been a huge hit since it came out. Kalra says he has done no marketing, he's just asked his friends to try it out. And this word of mouth promotion has led to more than 30,000 downloads for the app. 

The app also caught the attention of Apple, and they invited Amit to attend the Worldwide developer conference this year.

Source: FXTribune

Although he had built a random number generator program for his dad, he didn't have much knowledge of coding before writing this app. So first he taught himself how to write an iOS app. And in about 4 months, he was ready with the first version of 6284 Calc, and he has updated the app several times after that. In an interview with the Business Insider, he says, 

Every time I learn something in class, the first thing I do instead of doing the homework, is go work on it in the app first.
Source: LinkedIn

What were you doing when you were 16?