From my experience, most FOSS software is very user friendly user-centric / user-focused, while proprietary stuff is shit. What is the most notable exception to this rule that comes to your mind?
Edit: With user friendliness, I don’t mean UI design, but things like how the software is handling user privacy, whether it sees its users as users or as money-making cattle, how it handles user feedback, compatibility with other software the user uses (vs. vendor lock-in), configurability, and similar issues.
Edit2: I was made aware that user friendliness is a defined term: https://en.wikipedia.org/w/index.php?title=Userfriendliness
Anki on iPhone. Pay one fee and it funds the other users but it’s forever.
Photosync small one time fee but you get an awesome app forever.
Pleco app. Has some add ons but well worth the money and no other fees.
Anki and Pleco… May I assume you are studying Chinese ATM?
Haha, yes. Used them for ten plus years to study it. Now doing more Japanese but sucking at it. Regardless Pleco is the best language app outside of Anki. No Japanese app can do handwriting like Pleco. If I encounter some old or unclean character in Japanese I still use Pleco