Can I capture from my Apple Watch?

Yes. The watch app is built for the case where the phone is not on you at all — on a run, in the garden, doing the washing up.

1. Open Jot Minder on the watch.
2. Tap to record and say the thing.
3. It is held on the watch and handed to your phone the next time they are together.

Because it is queued rather than sent immediately, being out of range does not lose anything.