@neon Very much. The electrical components themselves in electronics tend to be pretty well shielded, so as long as it's a pretty normal magnet, you shouldn't have any issues.
The thing in a computer that's most vulnerable to magnets should be hard drives, which phones don't contain.
Not to mention I've seen flip cases with some pretty darn strong magnet clips, but never heard of anyone having an issue
@miwilc @neon Well yeah. For actual effects to happen you have to buy a "proper" magnet. Button magnets from your fridge shouldn't do anything at all unless you put them right onto the platters inside. Still better safe than sorry though. But as long as it's actually inside a computer, magnets from the outside should rarely be enough to affect it