

Professionals use Adobe software because it is what they know and because it is the standard. But there is no reason you need to use Photoshop unless you are working with a company that requires Photoshop.
Photoshop is just an advanced image editor made by Adobe. On Windows, Mac and Linux, GIMP is probably the most well known alternative to Photoshop. It can do roughly 99% of the things that Photoshop can do, and, more than likely, far more than you are ever likely to need. Even as a professional image editor or artist.
I’m sure that there are several options for iOS, but I don’t know them by name.
MusicBrainz is an open source database of music. ListenBrainz is an open source service that captures your listening habits, if you’ve configured your music player (or Spotify) to use the service. It’s similar in nature to last.fm’s scrobbling.
ListenBrainz has a feature where once a week it will build a pair of playlists for you. One is stuff it is pretty sure you will like (based off of what tracks you have favorited) and the other is more… experimental. Stuff it’s not so sure you’ll like but is similar to things you have listened to and liked in the past.