does anybody know the app cleaner

Yes I use the AppCleaner. Good for deleting apps and associated files.

If the app has an uninstaller use it.

I doubt that AppCleaner is going to speed up your Mac - unless you're short on hard drive space. Some companies have uninstall instructions or even apps on their websites for uninstalling their software. Use these instructions/apps if at all possible.

I've used AppCleaner a couple of times just to get rid of as much auxiliary junk as I can... but my use of it is limited only to those apps which I know haven't made any system modifications.

Be warned - without instructions/apps for uninstalling is the best method of uninstalling applications. Use AppCleaner only as a last resort.

See thomas_r's -> How to uninstall software.

Good luck,

Clinton