This happened to me 2 years ago, so I know it’s really really tough. We put our old boy Stanley down on Christmas Eve and it was devastating. He was a long haired tuxedo that looked almost exactly like your sweet Belle.
I hope you take comfort in knowing that her last moments will be right by your side, where she likely feels the most at peace. And I also hope that you take care of yourself, take the time to grieve, and lean on your loved ones when you can.
I’ve been using Raindrop for about five years. The solo dev really impressed me with his responsiveness to user feedback, so I started paying for premium ($30/yr) even though I don’t really need the extra features.
I’ve used the mobile app, Firefox extension, desktop app (Linux and Windows), and the web app. All have worked flawlessly and have grown more feature rich without ruining the user experience.
The features I use the most are:
I haven’t had a chance to use the REST API, but it appears to be documented quite well.
Overall I’ve had such a pleasant experience that I’ve never looked at any other option.