The only potential risk I see with anonymous voting is some 4chaner is apt to create a bunch of fish with horrific names and use distributed IPs to upvote them to the top. I guess regular moderation could filter that out.
The first case would be an issue yes, although this app doesn't exactly strike me as something that an insane amount of people would be connecting to from corporate networks
It can work okay for apps that don't go to massive scale and where users aren't concentrated in the same place. The chance of another simultaneous user on your block/building/CGNAT isn't extremely likely.
