This program takes textual input and makes statistical analyses on the text. It will count all the one-, two-, ..., N-letter combinations and arrange them lexically.

Detailed usage:
You can write your input text in the textbox or into a file Alt+I or "Intput" checkbox toggles that. Filenames can be relative or absolute
You can see the output in the other textbox or put it into a file with Alt+O toggling the choice.
There are three other checkboxes that change the behaviour of the program: they are Alt+A, +C and +F respective to custom "A"lfabet (I don't know why alfa sound more natural ), "C"ase sensitiveness and scanning from word beginnings or "F"rom every position of the word.
Alt+S will start the program (usually the performance is about 1MB/s). Alt+E will exit. Processing time shows the time it took in milliseconds.

Don't know if it has a better name in English, but that's what it was called in school: "Täheühendite leidmine" (compund letter search? maybe )

Implementation in ASM
64-bit source+executable
32-bit source+executable
(64 is only *slightly* better ~2-3%)
4MB sample file made out of fragments of "Alice" from Gutenberg project.

Interesting subject. Statistical analysis of text is adapted in cryptology (some old ciphers may be broken that way).