My anecdote for the pile is that my apartment complex uses one of those apps to pay for laundry services, but is slightly less expensive than the coin based counterparts on the same machine.

What's even worse is that the app is incredibly poorly made such that occasionally some payments just fall into the void and either start the machine for free or require a double charge. Anytime I have reached out to complain about these I just get told to bring my phone closer to the machine.