Cellular automata are a computational model based on cells which evolve based on their own values and on the values of their neighbors. They are considered simple under the mathematical perspective, but despite that they are capable to generate complex behaviors. Several applications of such computational model include from chemistry reactions to fractals. Considering its importance, this works aims at showing the Cellular Automata Builder (CABuilder), a software tool built in Python which produces graphical representations and pseudorandom sequences from two variants of cellular automata. This software is free, open source and is recommended for researchers in cellular automata; for teachers and students interested in this computational model; and also for developers who demand pseudorandom sequences in their applications, such as in simulations, cryptography, among others.