Handoff lets you continue your current task on another device, from where you left off (it hands off the task). So if you have a text document open or you're writing an email on a mac, it will let you continue doing that on an iphone, with the text you entered on the mac already being there.
You can also make calls or send texts from a mac if your iphone is nearby.
IIRC a bug causes the CPU to sit at 100% constantly, that's why the fan runs at max. A sleep-wake cycle after boot temporarily fixes that problem and the battery life increases.
I started with a Digilent Basys2[0], it could be a slightly cheaper alternative to the Terasic DE0. It uses a Xilinx chip, has a free design/development software called ISE Webpack, which also has schematic diagram support.
You can also make calls or send texts from a mac if your iphone is nearby.