Oh my. Do use pgrep. It's much more robust (what do you do if you have to search for a process named "0:0"?), and you don't have to use pipelines and strange regex tricks (which will fail to work on zsh with "set nomatch" if you don't quote, for example).
How does this work?
grep treats "[m]yapp" as a regex, which will match "myapp" but not itself. That is, it won't match the exact string "[m]yapp" so the grep process won't show up in the listing.