apps are a bit like phones, computer, cars, etc.
what color, features, sounds, etc. do you like.
for example, I use and like virtual hope box. When I suggested apps to my dad, he did not like it. the audio was a little quiet, and mid pacific female voices. When it comes to selecting an app... does it have ads? is it easy to use? what is the cost? does it have the tools I want?
I think he ended up using the headspace tools.
There was a thread on the forums about apps.... the good ones are headspace, smiling mind, calm ... there are the most well known. The one I use was recommended by my psychologist. You can also do a google search for
mental health apps backed by science
hope that helps.