The bot reads all messages sent in the channel, and if a message is in the form of a known command (matched by regular expression or string comparison) then it will act according to what it was programmed to do.
You could let you app do the same thing, listen to all messages through the IRC connection. But then another thing to consider is where the magic is going to happen. If you read these votes in every instance of a user’s app, then you face the problem of viewers joining in mid-voting, and not getting the right information.
This could be solved by having an actual bot running on an account 24/7, or whenever you need it to be available. This bot would gather votes in one place and correctly get the total, then send it to each client using your app through the internets.
This beckons the question if you need an app at all. What is your app providing that is much easier/better than sending a chat command like “!vote 6” and reading a total sent from a bot alone? I’m not trying to rain on your parade - these are just questions that I would ask myself in your position to see my vision more clearly.