I did this as part of my wedding proposal.
I wrote up a simple web app that accepted two different secrets to "login" (one for each person). Once logged in, you were presented with a photo and asked for a comment (first thing that comes to mind or a reaction).
If only one comment was submitted, it would tell you to remind your partner to leave a comment. Once both parties submitted a comment, the photo displayed with both comments and a countdown to the next photo. The countdown varied from 12-48 hours randomly - to give me time to figure out when to actually propose. This ran for several weeks total.
It was fun to see our comments - sometimes they would nearly match. Or reveal something we didn't remember about a historical date/event we shared.
I eventually used the site to pop the question, and then made the whole thing into a photo book, including a word cloud built from each of our comments. Was really fun to see each of our most common words.
It was an incredibly simple, fun project using flask/sqlite on an ec2 instance.