+1000
kabat-zinn guided meditations with lots of silence, free
body scan: https://www.youtube.com/watch?v=D8oKWQiEWYs
10 min: https://www.youtube.com/watch?v=8HYLyuJZKno
40 min: https://www.youtube.com/watch?v=cQkzhyXEc-0
(many others, search kabat-zinn on yt)
you don't need an app.