The writers of App Store stories come from diverse backgrounds. Some might be tech journalists, while others could be app developers themselves sharing their experiences. There's no one specific group.
Well, Archive of Our Own (AO3) is often considered one of the best. It offers a vast collection of fanfictions across different fandoms and has a user-friendly interface. Also, it allows for a lot of creative freedom for authors.
Webtoon is pretty good. It offers a diverse collection of manga and often has exclusive content. Also, it's easy to navigate and has nice features like bookmarking and offline reading.
Comixology is often considered one of the best. It offers a vast collection from different publishers and has good reading features. However, it might depend on your specific comic preferences.