A list of related verses that either explicitly or implicitly talk about the same topic or theme as the verse(s) the person is memorizing.
For example: if someone is memorizing Exodus 34:6-7 also suggest to the user to consider memorizing other OT & NT verses that cite that verse explicitly or pull some key words from that verse.
I think this could help solidify in our minds that the Bible is one unified story pointing the reader to Jesus. I think suggestions between the OT & NT could really drive home the congruency of the entire Bible (moments where Jesus quotes prophets or psalms comes to the forefront of my mind).