[GSOC] Implement calculator app

[Rustam Hadipash]

Hello Developer Team,

My name is Rustam Khadipash, I am a forth year student in Computer Science
at Pusan National University. This summer I would like to contribute to
your project, however I do not have experience in contributing to open
source societies so far. Therefore, I would like to start with not a
difficult project as "Implement calculator app". I am currently writing
proposal and would like to know whether there is an additional information
about the project I need to know and how I can get started on the project.
Thank you

Sincerely,
Rustam Khadipash.