...measure blood glucose levels using non-invasive methods...
An excellent idea; invasive methods are so vague[0] - because they're typically performed once a day, and even in blood sugar measurements, Nyquist will win - that a non-invasive method of instantaneous measurement will probably make a lot of people very happy.
(Though I'd prefer it didn't come with all the baggage of an apple 'watch' but it's likely that the technology will find its way into other devices. And we might hope that unlike HbA1c tests it's not confused if you happen to be missing a spleen).
[0] As in, it's accurate, but only for the time at which it is taken. It gives little or no information as to trends over time. If you want to manage your blood sugar, you really need to be able to sample faster than it changes significantly.