I used to have an A500, and this kind of thing started to happen after the update to ICS. What finally helped was doing a factory data reset, which probably cleared out junk in the system left over from Honeycomb. After that, no more freezes or crashes! Keep in mind this will wipe all of the local data on your device, so make sure everything is backed up (all of your Google data like Gmail and Google Contacts should already be on the web anyway). You'll have to reinstall all of your apps as well. But it might be worthwhile to make your device run more smoothly.
Thanks for your help. I did a factory data reset one time and then Google restored all of my changes but that is always so frustrating. I uninstalled a lot of apps that I didn't absolutely need but I might have to resort to another factory data reset because the tablet keeps freezing.
Sorry to take so long about responding. After the factory data reset I couldn't remember which app I use to ask the question.