Geometry Dash tools
GD save decryptor
Password finder

Japanese learning
If you don't know something, just submit an empty answer! It will tell the answer to you and add a note so you can learn it faster.
Learn kana (mixed hiragana+katakana)
Learn hiragana
Learn katakana
Learn katakana (Hiragana input instead of romaji)
Learn words (Hiragana knowledge is required). There's a total of 41 levels, totalling around 2000 words.

Alt codes
Alt codes (CP932 encoding)
Alt codes (CP1250 encoding)
Alt codes (CP1251 encoding)
Alt codes (CP1252 encoding)
Alt codes (CP1253 encoding)
Alt codes (CP1254 encoding)
Alt codes (CP1255 encoding)
Alt codes (CP1256 encoding)
Alt codes (CP1257 encoding)
Alt codes (CP1258 encoding)
Theoretically I can add other CP's, just open an issue.
More projects are coming!