If you are waiting to install a new OS (such as the Yosemite Public Beta) because you are worried about compatibility issues, check out the Application Compatibility Table over at RoaringApps. There are compatibility charts from Snow Leopard up to Yosemite, and from iOS 5 up to iOS 8. If you don't see an app listed there and you know its status, you can submit it to the list. It's a great resource that is easily searchable if you need to determine what does and doesn't work.
Check It Out: OS X and iOS Application Compatibility Table