No it’s not native. It’s a JavaScript layer on top of native code that allows iOS and Android apps to share a codebase

You could try Expo if you know React

My first thought is to rank items by totalVotes / score. This would prioritize posts that get lots of votes in both directions.

Example:

def getControversialScore(upvotes, downvotes):
  return (upvotes + downvotes) / abs(upvotes - downvotes)

getControversialScore(50, 10) # 1.5
getControversialScore(4, 5) # 9
getControversialScore(6, 30) # 1.44
getControversialScore(30, 28) # 29