My screen is small, so I don't want to use those markdown editors which split their window into source section and preview section, I want to one window for both editing and previewing, so I developed Typora. It's still under development so it's still an alpha version.
Haven't consider that. But the windows version is based on node-WebKit which has a built-in support of cross-platform, so there maybe a Linux version in the feature.
To me, one big issue is that you cannot use markdown to present everything, for example, one cannot use it to produce something like <pre>`d`<pre>, I mean he cannot use ``d`` to do that, right? Also you cannot write
```
```markdown
## HEADER
```
```
to produce a fenced code block which contains a markdown source code for code block.
Also, different markdown editor use different markdown parser. So, same source code will be rendered differently in different editor.
This makes a similar concept with marked2 (http://marked2app.com), you write markdown on any app you like and then preview it using another tool. But personally, I prefer to do the previewing and writing on the sometime. So my ideal markdown eidtor is something like Typora (http://typora.io)