Calus Plus, free-to download and use inventory software that will take over your business with ease is what I would call a solid program. Of course, it's not quite as good as the heavy-weights in this niche, but for an average or small-sized business it's a great choice to start with. It'll allow you to manage appointments, invoices, customer information, supplies and so on. Calus has the capability to connect with your accounting software as well. This software package has a lot of features that make it well worth considering.
There are a few things about this program that do irritate me, however. The first is that the interface is very clunky and it does take a while to get used to it. Another problem I have is the fact that the program updates itself constantly. This causes problems when using the program on a laptop. I don't understand why it updates itself at all, especially if it's not running in the background and not on your system. And since it's free, I'm not sure why anyone would want to download and run this program on their computers.
Overall, the program is pretty good and provides all of the important aspects that you could want for your business. The biggest problem is that it updates itself constantly and doesn't run in the background.