Squash

There are a couple of squash and other sports apps in Connect IQ.

I can only find 1 squash app. Unfortunately it only works on vivoactive and not my 735xt. Are there any other?

What are you intending to track? I assume its only possble to track HR over time, and not a lot else.
In which case a custom profile based on indoor other seems as good an option as any.
Incidentally, I've never found the built in HR sensor any good for squash when I've tried it.