I use different apps depending on what I need. Sometimes I do relaxation or mindfulness, and sometimes I just do nature scenes.
I'm newer to meditation so sometimes I just go to YouTube and look up meditation to try something new. I do guided meditations, vipassana, and sometimes just sit there and relax and free my mind.
I like to do mindfulness meditations. Where I'm able to focus on the breath or a specific part of my body. Ones where I can zoom out and look at the bigger picture on what's going on really help. Especially when I'm dealing with a problem it helps to get out of your bubble.