A few years ago, when I was still working at home and working on a laptop, I had heard of Gmail Notifier, a new iPhone program that lets you download any applications to your iPhone. This program is very similar to the free Mac applications available online. The thing I liked about the application was that it worked seamlessly with my Mac.
One problem with the free applications for Macs is that they don't work with every version of Mac OS X. For example, I'm using version 10.2 of Mac OS X and Gmail Notifier works fine. However, in version 10.1 of OS X, Gmail Notifier starts showing ads on my screen when I open the program. I can't get rid of the ads, which makes the application not worth using.
Another issue with Gmail Notifr on the Mac is that it doesn't allow you to make multiple downloads from the same application. Instead, it will download the latest version that you can use. This was really annoying to me, because I always wanted to have the latest version of my application installed in my Mac before I started working on it.