Insight timer is a very good app for guided meditations and it includes a timer with bells and other preferences, for people with some experience in meditation. The user interface is beautiful, very minimalistic. You have thousands of guided meditations for many different things and lectures, groups of many kinds (women who meditate, reiki and many others). Every year they do “365 days together” where people have to do a meditation every day and there is one for each day. There are statistics about your practice. It’s what I recommend for beginners. I also recommend that you don’t do the chakra meditations, if you’re a beginner. If you are interested in reiki, first find a local reiki master. Oh and there are also binaural beats. Happy meditating!