After 4 attempts of submission App Store finally has published the app for e-maxx.
How I came to the idea of developing an app?
During riding in a bus I decided to read some algorithms on e-maxx cause have nothing to do rather than watching in the window. I opened the Chrome and started reading some article. After finishing reading decided to switch to another article though I found that it is a little annoying cause fonts are too small and internet connection is a little slow. So I came to question why not to create app which works offline and easy to use from phone. I read that all content in e-maxx are Public Domain so I decided to write the app.
Writing the app did not take much time but parsing the content and rechecking everything is a long process. Thereafter, there were some argument with App Store regarding the design. Finally, the app is in the App Store.
Currently, the app is in russian and for iOS only. I am not planning to write android version yet though if you want you can, The link to project is below. Thanks for you attention! 
P.S. Thanks e-maxx for copyrights.
The link to the app: https://itunes.apple.com/us/app/e-maxx/id1255128609?ls=1&mt=8
The link to github project: https://github.com/aatalyk/e-maxx