golf metronome's?

[HomerJSimpson]

Just checked out Tour Tempo in the App Store. Looks good, but £17.49? Seems like a lot of money for something that just counts a beat, especially as there seems to be quite a few free metronome apps avaiable, or am I missing something?
My pro advocates using a metronome, especially for putting.

Pretty sure that price includes a separate section for the short game too. It is expensive but with four speeds to choose from it is good. I try and use the slowest setting possible at times as I am so quick. Really hard to reign it in.