https://wccftech.com/todays-list-of-paid-apps-that-are-free-or-on-sale-at-the-play-store-including-cover-art-binary-calculator-pro-and-more/

This is a free mathematical calculator, which is able to add, subtract, multiply and divide numbers in binary format (used in computers).

Any number can be represented by any sequence of bits (binary digits), they are commonly written using the symbols 0 and 1.