My secret superpower.
If we were all allowed one secret superpower, mine would be the ability to mess with people's phones.
I'd be able to turn them off whenever I felt like it. Someone in the middle of a conversation would say: Hello. Hello? HELLO? Then, with a slight frown, they'd check their phone just as I simultaneously switched it back on. Nothing would seem amiss, they'd call back and after allowing a few more seconds of conversation, I'd do it again.
Or I might make a phone super slippery so the owner would keep dropping it. Imagine the person opposite you on a train was chatting away when for no obvious reason, the phone would just fall out of their hand. They'd maybe mutter a mild profanity, perhaps make some kind of comical attempt to catch it, then pick it up and carry on talking, before immediately dropping it again.
How funny would that be? How many times would they show it to the floor before giving up and putting it back in their pocket?
Then I'd make it suddenly get really really hot.