"Our cookies are tasty."
Translation:Nasze ciasteczka są smaczne.
The answer in the app is based on the basic, main answer. And obviously that answer has to start with a capital letter. It's a sentence, after all.
I'd say, that the app is generally very easy. Using the website is significantly more challenging (which doesn't mean difficult). My personal recommendation would be to use the website for learning new things, and the app only for strengthening skills.