why does my app dont open!
I can’t understand your question. 
Are you meaning that you have an problem to launch Mudfish app for android?
Then could you test How to check the basic functionality first? At least this should work on your environment.
If you’re asking about How to check the basic functionality section, you can pick any node. Please confirm that it works or not first for me.
처리해 드렸습니다. 확인해보시고 문제가 있으시면 언제든지 답글 부탁드립니다.
감사합니다. 정상 입금 환인했습니다.