Uguu.
cargo build --release
$ cat test.txt
The quick brown fox jumps over the lazy dog.
$ uguu test.txt
$ cat test.uguu
ぐぐぐうぐぅぅうぐぅぐぐうぅううぐ〜うぐぐ〜ぐぐぐぅぅぐぐぅう〜ぐぅぅ〜うぅううぐぅうぅぐ〜うぅぐぅ〜〜ぐ〜ぐ〜ぐぅ〜ぅうぅううぐぅぐぅぐぅ〜〜ぐ〜ぅううぅううぐぅぅぅぐ〜ぐぐぐぅ〜ぐぐ〜ううぐ〜う〜うぅううぐぅ〜〜ぐ〜ぐぅぐぅぐぐぐ〜うぅうぅううぐ〜ぐうぐぅぅうぐぅぐぐうぅううぐぅ〜うぐぅうぐぐ〜ぅぅぐ〜ぅぐうぅううぐぅぐうぐぅ〜〜ぐぅぐ〜うぅ〜ぅううぅぅ%
$ uguu -o test.txt test.uguu
$ cat test.txt
The quick brown fox jumps over the lazy dog.