1) Bing search is terrible. Why not use Google image search per the Fluent Forever method? So much better.
2) Ability to add a new word, even if it is from the list of words supported. Without this I still am stuck to Anki
3) Laggy. Need to provide feedback such as “loading” immediately when a press is registered. Otherwise, it seems buggy and non-responsive
4) Sound playing is hit or miss.
I am familiar with the method, using iPhone XS and beginner Russian. I love the app and can almost see it replacing my Anki system fully. To be more mainstream, the app needs to feel less laggy and download resources, such as audio and images, locally. Cached perhaps. Also, it needs to be a little more polished. The UI is nice but it looks behaves slightly different than a native app. Small fonts and such. Maybe just compare it to other iOS apps.