What criteria do you use to choose flashcard apps for studying?

Choosing the right flashcard app can be quite a challenge given the sheer number of options available. Each app claims to enhance retention and facilitate effective studying, but they often feature different approaches like spaced repetition, gamification, or collaborative tools. For those who have experimented with various apps, what factors do you consider essential when making your choice?

Navigating the selection process can be tricky, especially when trying to find the app that aligns best with your personal learning style. What recommendations do you have based on your experiences? Were there any features that significantly impacted your studying, and are there apps that fell short of your expectations?

I usually look for spaced repetition and ease of use. I found that Anki really helped me retain info better than others, especially with its customizable cards. But some apps I tried felt cluttered and just distracted me more than helped, so simplicity is key for me!