I recently tried the Rapala line counter you have pictured. I was not aware when I purchased it that it will not work with spinning reels, because of the way the line lays coming off the spool, or at least I couldn't get it to work accurately. I think it is designed for conventional reels only. I also only wanted to use it for spooling line to reels.
I ended up going to the local high school football field and used the yard markers and goal posts to get an accurate reading of how much line I could get on the reel, and subtracted that from the spool to determine how much I had left.
Eventually, I'll probably look into buying a second-hand line spooler.