You spot someone you fancy on the Tube, fantasise about your deliciously perfect life together, name your three kids and… You’ve reached your stop and your soul mate has vanished into the murky ether of the underground forever.
When you see someone attractive you simply have to open the app, find their profile and send them a Spark.
Yes, your Tube crush will need to be signed up to the app too, so its usability ultimately depends on how many people create an account.
The recipient will only receive your Spark once you have parted ways, saving any potential embarrassment and allowing you to maintain a certain air of mystery.
CEO Dave Marsden, 24, who co-founded the app with Gabriel Sharp, 25, hopes Spark will help people to forge connections with potential suitors that might otherwise be missed.
“Every day we see people that catch our eye, and in that second we form a picture of who they could be and how we might get on," he says. This is a real person who we all-too-often fail to speak to and we want to change that outcome.” As we have seen this week, the London Underground is a hotbed of attractive individuals.
As reported elsewhere in Telegraph Men, photos of good-looking chaps published on the Tube Crush blog have become absurdly popular (especially in China, for some reason).
Now, instead of just taking sneaky snaps and submitting them to Tube Crush, admirers will be able to make contact by Spark.
Demand for the app is already high, with over 4,000 users signing up before it launched last Sunday.
That's still some way behind Tinder's estimated 50 million users, but it's a positive start, and is probably a reflection of the fact that Spark offers something different.