Fitch is a formal logic system for proofs. To use this application input values for each part of the expression as well as what you think the proper values of the connectives(implication, and, or, etc.) should be then press evaluate. The program will then tell you whether you were correct or not. Valid inputs for the variables/connectives are T/t or F/f. The program will tell you if your connective guesses are correct or incorrect. If there are multiple connectives, it will evaluate them in left to right order prioritizing parenthesis first. It will evaluate each connective, so if you get an early part incorrect it will not proceed.
Here are some truth tables for reference. The last coulmn represents the connective value.