This is an old app that seems to be working in Yosemite according to users.
To install depends on how the author set it up. You will either have to double click the package or it may require dragging it to your applications folder.
If you have trouble you may have to open your system preferences -> security & privacy and click on the general tab. At the bottom of the general tab there is a lock icon. Click on it. A box will pop up and ask for your admin password so the lock can be unlocked. Once the lock is open under "allow apps downloaded from:" change the selection to anywhere. That will allow installation. (You might see a message on the page that says the app tried to install and you can just give permission there.)
Make sure to change it back or you will be opening yourself up for potential problems. I hope this helps.
Thanks, pm-r. No, it's not the size of the cursor, it's the color. I'm working with something which has a black background, and manipulating things is hard not being able to see the cursor. 'Preciate the help though.
No, pm-r, I didn't try that either. When you say "just joking" it sounds like you're apologizing for suggesting something I might already know. Don't be sorry. I'm a newbie and DID NOT know that about changing the color on the mouse. That might be an even simpler solution for me and I'll certainly give it a try. Every time I get on this forum, I learn something new from you old hands. Many thanks