Game dev experience re: Twitter, made a couple random Twitter friends, but TBH I don't think it's all that worthwhile. It's a good way to feel productive when you're not, but I wouldn't really recommend sinking too much *productive* time into it.
I'll share some stats and you can make up your own mind:
Followers: 16.2K, for 26 tweets this month, they've made 38.4K impressions and I've had 4K profile visits after following roughly 800 new indiedev accounts (I only follow devs). Our free game that's been pinned for over 6 months has only seen 50-100 downloads, and I don't know how many of those are driven from Twitter, or simply the store when it came out.