Helps with everything; opening packs, sorting through collection.
And I know in theory it only affects certain comps in battlegrounds, but since I did this my rating's up about 1,500 points in the last couple days. I've had a few APM Pirate comps that wouldn't have worked with slow animations. But really I think it makes you better with every build. Just having the ability to think about your turn without worrying about coming up short because you lost 10-15 seconds on animations is huge. Especially those turns where you find a late triple and it throws your plans awry. Trying to get that discover processed and onto the board was always majorly dicey with slow animation speed.
I’ve done it for my iPhone and Android. It works, but it also doesn’t. While making it smoother and easier to use and make fast decisions, the overall time spent is the same. There’s just more frames per second, same number of seconds. If you’re playing APM decks or battlegrounds on mobile though, it’s a noticeable improvement, but it will drain your battery at least twice as fast.
edit: the file you are looking for is called options.txt. It should be in the main file once you open the HS files on your phone. Mod the file on PC and drag it back, don’t forget to replace the file. It takes about 5 minutes.