Guess It is a word-deduction puzzle: a hidden word, a set of short clues, and the job of working out both which letters it contains and where they go. It sits somewhere between hangman and a crossword clue.
The clues are the interesting part — they narrow the field without giving the answer, so solving is a process of elimination rather than a lucky guess.
It gives you clues about the word's meaning as well as its letters, so deduction plays a bigger role than pure letter frequency.
Vowels — E, A, O, I — then the common consonants T, N, S and R. They appear in most English words and anchor the word's shape.
Yes — tap letters. Nothing to install.