1) Insight Timer is an app you can download on your smartphone that gives you access to tens of thousands of free meditations. Another neat feature it has is the Timer. The Timer allows you to set a duration for silent meditation to do on your own. This can be beneficial for those seeking to keep a mindfulness practice. You can also visit their website at insighttimer.com
2) The Breathing App is another smartphone download dedicated to helping people regulate their stress by engaging in something called "Resonance Breathing." This is a specific breathing method whereby you follow along with the app as it guides you to breathe at a certain rate. This type of breathing exercise is specifically designed to take you *out* of fight or flight mode and bring you back to your normal baseline. This is highly recommended for persons who may be suffering from post-traumatic stress.
3) Audio-books can be immensely helpful for those of us who may be on the go constantly and don't have time to dedicate to reading. For trauma I recommend The Body Keeps the Score by Bessel Van Der Kolk, MD. It delves into trauma in a way that makes it easy to understand. It can be somewhat triggering (warning) yet also validating for those who have experienced major life traumas. For relationship stress or communication issues I often recommend Non-Violent Communication by Marshall B. Rosenberg, PhD. This book breaks down language in a way that uncovers our own internal biases and points to new and more helpful ways to express our own needs, in addition to learning how to identify the needs of others.
4) Mood Tracking Apps: Any mood tracking app that can help you track your emotions can be beneficial for identifying patterns in a more objective way. The better data you have - the better we are able to understand your moods and what may be affecting them. Daylio Journal, eMoods Bipolar Mood Tracker, and MindDoc: Depression & Anxiety can all be great choices depending on what your specific needs are.