[chuckles]
I used to develop "early" interactive stuff for corporate clients.
Part of my job was to evaluate what the client "wanted" as opposed to what could (and SHOULD) be done.
Such an app would amount to merely a "sound effects player" - at minimum, you would have to
- open it
- select a sound
- play the sound
There is no possible way that this app would be able to perceive that you were about to train your dog.
You could use such an app in a "session" -
- know that you are gonna train
- select the sound - to have it READY to tap
Another thing... I am unsure that an Apple WATCH would have much "ooomph" - how loud would ANY sound actually play?
sound effects app apple watch site:apple.com - Google Search
The first few I looked at all require iDevices - Apple WATCH is NOT an iDevice
In my position as consultant to a client, I would tell them, "Get a clicker"