I was offered a line spooler to review so I did. Any way, I'm old school, I used a bucket, and heavy book to spool my reels, but this thing works well and the neat thing is you can use it to remove line from your reel. Check it out :

Wouldn’t you need to turn the line sideways for a spinning reel to avoid line twist? It seems like it would work great for baitcasters though.

yes, there is a right way and a wrong way for spinning reels.

That is similar to what I use but way more complicated. I take the line off the top of the spool with my reels right side up. I have been doing it that way for at least 20 years with my Shimano spinning reels and have never had line twist. Other brands may not work that way so I can’t speak for them.