Following is a little utility I've coded recently, to automatically add foreign accents (diacritical marks) into Slovak, Czech and Polish language in real time (as you type). Utility works in anywhere in Windows, as demonstrates the following video showing how the program works inside the Notepad, which as we all know, does not natively include such functionality.
Words in the text typed without accents, such as this:
Slovak: Automaticke pridavanie makcenov, dlznov ci hacikov do Slovenciny.
Czech: Automaticke pridavani hacku , carek ci hacku do Cestiny.
Polish: Automatyczne dodawanie akcentow do Polskiego slowa.
Would automatically be turned into accented words:
Slovak: Automatické pridávanie mäkčeňov, dĺžňov či háčikov do Slovenčiny.
Czech: Automatické přidávání háčků , čárek či háčků do Češtiny.
Polish: Automatyczne dodawanie akcentów do Polskiego slowa.
Here is a YouTube video demoing capabilities of the program: