I’ve researched a ton of upper math software, as my son will be there soon (we homeschool), and this is by far the best I’ve seen. It’s not cheap, but it’s completely worth it.

http://www.videotext.com/algebra.htm

For English/writing, I recommend IEW (Institute for Excellence in Writing). They have a complete writing course with grammar built in (the high school levels get pretty technical, but still easy to follow). Basically, they integrate grammar with writing and show you the application of it as college prep. You can get the complete course, or you can zero in on grammar (Fix-It) or essay/research writing (go to the writing supplements section). These are meant as either upper high school or multi-level, including upper high school. They are more than sufficient to prep you for going back to college, and most can be done in a short amount of time.

http://www.writing-edu.com/

These will both play on your computer, and except for the elementary levels of the writing course, they are not made for children.

Not sure if that’s what you’re looking for or not, but they’re the best I’ve seen and easiest to work with from what I’ve researched. Good luck!