MathXpert has produced tutorial software programs for algebra, pre-calculus, and calculus.Calculus Assistant includes both of the lower level modules plus thorough coverage of calculus. It is available for free as a single download. It runs only on Windows systems, although you can run it on a Mac system using Parallels or Bootcamp or on a Linux system using WINE.
Each module is set up in a similar fashion. The Algebra Assistant shows a table of contents with topics and subheadings. The student selects the one covering a problem they are having trouble solving. The program includes many sample problems, one of which is likely to be similar to the student's. The student highlights a part of an equation to be dealt with then the program shows a list of possible operations. Hints for which part to tackle or which process to use can be accessed. The program works step-by-step through the problem. If a student prefers, he can substitute his own problem's numbers into a sample problem, or with a bit more effort, he can create his own problem. The program can also graph solutions, and both graphs and solutions can be printed out.
These are excellent programs, and it is surprising to be able to access them for free.