You don't really need a gadget to meditate, any more than you need an app to go running. But it's nice to be able to keep track of your progress, and maybe even use the data to see how variables like sleep or exercise affect your ability to stay focused and relaxed.

I wrote a small app to record short meditation sessions using a NeuroSky MindWave [https://github.com/zenobase/zenobase-mindlog]. But I stopped using it because getting this device positioned correctly was a pain...