The idea is so simple it's a wonder no one has thought of it before. The app takes satellite images of search and rescue team routes, divides them into millions of small plots and assigns them to users to monitor. The app doesn't make clear how long you have to monitor your assigned patch, though.

Once you spot what you think might be a boat, you can flag it and tag with a description. Figuring out if a vessel on your plot is a migrant boat in trouble is a bit challenging, though. I thought I was looking at a picture of the night sky when I tried the app, and wasn't sure if any of the specks in the image were worth flagging.

I tried tagging a shadowy blob as "nothing," and I Sea asked for my name, passport number and email before letting me submit my report. That's a pretty good deterrent for would-be pranksters, but the form can also be filled out with dummy info.

After posting my report, I was returned to the same plot of the Mediterranean sea I had been assigned, with no indication of when I would get a new region. The app sends your report to "relevant authorities" for processing, before sending a rescue team out to your tagged location.

It's wise that I Sea is reviewing the reports before sending its teams out on wild goose chases, but that vetting alone could become more of a hindrance than help. However, compared to the dozens of donation apps available, I Sea appears to be helpful in a much more immediate way. For those with time and good intentions, this might be a helpful way to spend some downtime.

Update: Several people have pointed out that the app may be a hoax. It appears to display the same image for every user, and some claim to have found other oddities in its code. The title has been pulled from the App Store. Neither MOAS nor Grey Group have responded to our requests for clarification.