Mathtools: Algebra One Edition is the ultimate program for the algebra one course. It includes everything you need to excel, features an easy to use interface, and is by far the most feature-packed algebra program available!
Full list of features: Equation Solver, Polynomial Factoring, Radical Simplifying, Pythagorean Theorem, Distance Calculator, Quadratic Equation, Midpoint/Slope/Intercept/etc, System of Equation solver, Basic Statistics, Rational Equations, Recursive Sequence, and Polynomial Division.
This program is a no-brainer for any algebra course. While the main focus is Algebra One, it will serve you well in pre-algebra, geometry, algebra two, and pre-calc. It is compatible with the TI-84 Plus CE and TI-84 Plus C Silver Edition graphing calculators.