past few years, and the biggest problem I've always run into was that not
a single one of them handle ANSI correctly.
You have to go into the settings and find where you can select the encoding. Usually it will be set for UTF-8, and you need to change it to CP437. Then you also need a font that has upper ascii chars, but a lot of the monospace ones do. In Putty on Windows, for example, you have to select both CP437 encoding and the Terminal font.. but I think in ConnectBot for Android all I had to do was set the encoding.
Depending on your screen size, Termux can be an OK BBSing terminal. You might need a CP437 wrapper, tho (github.com/keaston/cp437).
--- NE BBS v1.16 (linux; x64)
* Origin: NE BBS - nebbs.servehttp.com:9223 (21:3/193)