Android: If you have an Android device and a Mac, you can transfer files between them easily with Droid NAS. It's simple, it's fast, it works without cords, and it doesn't even need anything installed on the Mac.
All that you need is for Droid NAS to be installed on your Android device and it to be connected to the same Wi-Fi network as the Mac. Hit "Start Server" and you'll get a message that Droid NAS is visible in Mac's Finder. Sure enough, if you open Finder, you'll find it connected as a device, ready to perform file transfers.
You can set different profiles to share different data, with the options toggling between SD card, camera, downloads, music and photos. Once you see it on your Mac, it's as simple as a regular file transfer.
Some Macs might have trouble with this and get a "Connection Failed" error, prevalent on many machines running OS X Mavericks. There's an easy workaround for that too. In Finder, hit Cmd+K and enter the IP address Droid NAS shows when you create a server (such as "smb://192.168.1.35:7777") and append the name of the folder you want to access with a slash. So for example, with the above IP address, if I wanted to access the SD card or the photos, I'd need to do this:
Open Finder and hit Cmd+K In Server Address box, type:
(to access the SD card)
(to access photos)
Again, Finder will open the device and you are ready to start transferring content as you want. Since it doesn't require any cables or any software installed on the Mac, it actually makes sense to have Droid NAS installed on your Android device even if you don't have a Mac, just in case you need to make a Mac transfer some day. Of course, this is only for file transfers, and you will need to do more to seamlessly sync your Android and Mac.