Is the app foss?

No, and even worse, its only for apple devices lmao. These kids are so unserious in their activism it would be funny if it werent so sad. If shit hits the fan, this stuff will go down instantly and im sure it has no backup plan for a Tor based or p2p service. Activists in the US should start using Briar. This situation is exactly what it was made for and people have to get their tech game up fast or they will be done for. Get a shitty 80$ android phone if you only have an iphone. Install a panic trigger app that will wipe the phone if you are in trouble.

On ICEBlocks website it says:

Modeled after Waze but for ICE sightings, the app ensures user privacy by storing no personal data, making it impossible to trace reports back to individual users.

Which worries me, because if its closed source then thats a worthless promise and actually makes the app a perfect candidate for a honeypot or backdoor.

apple is the majority of the market, no? so if e.g. a company wanted to get a product out for a client asap, apple would be the market to aim for.