A few schools in our district have been using a literacy product called Lexia. It's considered by many to represent the state of the art in RTI software and has been really well-received by both teachers and students. A recent upgrade to the software and new licensing that the company has proposed for us could expand access to this software from K-4 to K-8 and allow home access for students as well.
So what's the downside? Lexia is expensive. As in I could put together a few really nice computer labs for what I'd be spending on Lexia. Of course, these labs aren't of much use without software and Lexia does a great job both of remediating and allowing students to work ahead. Unfortunately, with RTI software, you actually tend to get what you pay for; aside from some university pilots, there aren't many free and/or open source applications that really build literacy skills across a spectrum of students. Lexia does, making individualized instruction easier for classroom teachers and providing really usable data on student achievement and areas of weakness that teachers can use immediately with their kids.
Which still leaves me asking, to Lexia or not to Lexia? I think the answer, assuming the financial powers that be in the district can scrape together adequate funding, is to Lexia. The new computers that we've installed district-wide need to be more than glorified word processors. We need to allow students to access a wide range of educational software beyond Google and Wikipedia. Even beyond the available free educational software, there is a real body of software based in serious pedagogical research that, unfortunately, costs money. However, if I can make it easier for my teachers to effectively differentiate instruction, then I'd be remiss if I didn't push for products like Lexia in the schools.