Are there any good apps for monitoring glucose level?

I’ve been learning about how hormone insulin affects weight gain and metabolism, and it’s pretty eye-opening. Apparently, imbalances can lead to increased fat storage, which makes me wonder—how do you all track your insulin-related health metrics? Are there any good smartphone or tablet apps that help monitor glucose levels, diet, and activity? I’d love to hear what’s worked for you and any tips for keeping insulin levels in check. Also, I wonder if I will be able to do it on my Apple watch!