M.J.
Believe me, You are sooo not the only one! I had the same problem with my son before, as well as the whole problem with he only took so much of his medicine. So it became a guessing game as to how much more to give him. When that happens, I've just come to the conclusion to not give any more medicine until its time for the next dose. But that's just me. I'll keep a look out for the dose keeper though. It sounds like a truly amazing product!