I have been using Headspace since 2011(>10000 minutes) as well as other guided meditations/reading around the topic, and one Gawler retreat.

Late last year I thought I should trial Sam Harris's Waking Up Course, which is really a daily guided meditation plus some "lessons" that provide explanations. The books he has written certainly provide food for thought as does his podcast.

The Waking Up course is via an iPhone or Android app and I can say hands-down has been the best meditation app or resource I have used to date.

https://itunes.apple.com/us/app/waking- ... 36395?mt=8

Little bit pricey, but truly excellent.