What do you have in mind for the style and theme of the app?
It should have an awesome design.
On the left, you can choose your daily exercises (1st box from the top) and a lot of learning methods for vocabulary (2nd box from the top).
On the right, you can learn the words.
In the top right box, you can see buttons for
- changing the language (arrows)
- getting more information (icon with question mark)
- "I didn't know" (red X)
- "Show answer" (eye)
- "I knew the word" (green icon)
Underneath you can see the English word first (without the Spanish translation).
After pressing the "eye" icon, you will see the Spanish translation (as you can see in this picture).
After that, you press either the red or green icon to indicate if you knew the word or not.