Nothing for them to install: It opens in whatever browser they already have.
Works in any chat: Anywhere you can paste a link, the letter arrives.
You can take it back: One tap and the link stops working, for good.

How it works

Four steps, and nothing for them to download.

Pick the occasion, type the question, add a note if you want one. It takes about a minute.

Copy it and paste it into WhatsApp, iMessage or Instagram. Nobody has to install anything.

It arrives sealed with their name on it. They tap it, it opens, and your question is inside.

Yes is easy. No runs away. Either way they get a card they can screenshot and send back.

What people send

Three things the research says about how people receive a letter like this, in the researchers’ own words, and what each one changed here.

It comes at little cost, but the benefits are larger than people expect.
Amit Kumar, on Undervaluing Gratitude, Psychological Science, 2018
In three experiments, people who wrote a sincere letter overestimated how awkward it would feel to read, and underestimated how good.
So the note gets the room, not the question. The part most people would leave blank is the part that gets read twice.
…a form of cognitively induced deprivation that arises from the perception of a gap in knowledge or understanding.
George Loewenstein, The Psychology of Curiosity, Psychological Bulletin, 1994
That is his definition of curiosity. Not knowing one specific thing is mildly unpleasant, and the only cure is finding out.
So the sealed envelope says who it is from and that there is a question inside. Never which one.
We actually don't choose between experiences, we choose between memories of experiences.
Daniel Kahneman, The riddle of experience vs. memory, TED, 2010
And what a memory keeps, in his words, are “changes, significant moments and endings.”
So the ending is the most carefully made screen on the site: their photo, both names, the question, the date, in the colour you chose. Made to be kept, and to be posted.

It started with valentines. It turns out people use it for the whole wedding party too.

Worst case they say no and you have a funny story. Best case you have a card you keep.