Still some apps seem to have problems with unicode terminals/output. I am looking for a app (or script) which prints out some unicode formated text and line drawing (like ncurses). Thus help to figure out if the app is broken or the (terminal/env/ssh-client) settings are wrong. Which app does this and is most likely to be installed on a linux system?
Just create a text file with some Unicode characters and use that as your testcase. You can then use
cat or shell redirection to send the file's contents to another program to test whether it works.
If you want more details, give us a specific example you're considering.