If you set `conceallevel' to 2 and use syntax highlighting, you should get it in vim without any plugins needed (although I have only neovim installed).
For example, \AA -> Å, $\pm$ -> ±, and {\'e} -> é.
Does anyone else find this "feature" really annoying? I always set conceallevel to 0 but vim seems to constantly find a way to replace my code with unicode.