Tara Brach is an American psychologist, author, and a teacher of Buddhist meditation and mindfulness. Please check out her guided meditations that are designed to help with insomnia and anxiety. I will be studying with Tara, Jack Kornfield and colleagues for the next 2 years at The Greater Good Science Center at UC Berkeley as I complete my teacher training certification in Vipassana or Insight Meditation.
If you are looking for a mindfulness app, I highly recommend Waking Up which was designed and is hosted by Sam Harris who is a neuroscientist, a philosopher, a well-known author and a long-time practitioner of Insight Meditation. There is a free trial period, I think one month, but if, after that, you cannot afford the yearly subscription ($99.99), you can go to the Waking Up website and scroll down until you find the tab “request a free account”. There is a 28-day introductory course on Mindfulness Meditation that is excellent. Plus, there is so much other content about the theory, the science and the practice of mindfulness as well as long, stimulating interviews/discussions with authors and researchers in related fields.