Show me your code

[h1542462994]

You say it is an opensource code software, but where is the source code.
And,there are a repository whick is very similiar with your release apk. So I can make sure you copy the code but not share the source code.
here is the source code

[Ryhat]

You are right

[kLiHz]

Well, I've visited the repo indicated by @h1542462994 and it seems like that repo was inspired by this MarkdownX, as said in the project README. So, in my opinion, the developer of MarkdownX might not be copying others.

[cross-hello]

As it is commend from the README from qinci :

部分界面和功能仿未开源的MarkdownX软件

So that is the answer,