These apps can be downloaded on iOS and Android devices
Daylio
Happify
Psychologist-approved positive mood-training program
Has engaging games, activity suggestions, and gratitude prompts to kick negative thoughts, nix worry, and decrease stress
Happify is technically free, but to access more advanced options, and detailed statistics, you have to pay—$11.99 a month.
Link for Android devices
Link for IOS devices
Insight Timer
Mindshift
Reflectly
SAM
Shine
WYSA