Tap Codes
Tap Code, short for Polybius Tap Cipher, is a simple substitution cipher used to encode messages by tapping sequences corresponding to letters in a 5×5 grid. It has been historically used in situations where audible or tactile signaling was necessary, such as in prisons or covert communication.
Bootstrap
Bootstrap, short for Bootstrap Framework, is an open-source front-end toolkit for building responsive, mobile-first websites and web applications. Originally developed by Mark Otto and Jacob Thornton at Twitter in 2011, Bootstrap can be downloaded and used for personal or business projects via getbootstrap.com/download.