Consider alternative icon for boost action

[cmho]

Using the "share" icon for reblogs/retweets/boosts seems a little confusing to me—that icon makes me expect that I'm going to get options to share the post externally, like copying the link or sending it to Twitter. I realize it's not a thing that Instagram does, but it might be better to use the Retweet icon just to make it clear what it actually does so people aren't accidentally boosting stuff they don't intend to boost.