A web-based cryptography experiment I made for fun. No need for a live server—just run BaseREPR.html.
Can encrypt/decrypt any string containing only the following:
0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-._+!'(%,$/:=*;)?<>@&^%|[]{} `#\\~\t\n
This is an earlier version of a better, more recent desktop version I also have publicized on GitHub.