As a dog owner for 15 years I can honestly say I have never felt the need to track any of this. I'm curious, why would you need to? Do people forget to take their dogs for walks? Most dogs come with builtin alarms consisting of wagging, slobbering and pouty faces. Mine even runs back and forth between me and the bowl when he's hungry, hard to not notice the hint.

My first question with such a project are: how will you pay for that service, and what features will I have to pay for in the future?

Don't take me wrong. This is a great idea, and I'll have a dog soon so I'd love to use such a page, but I'll dump my data into this and if I decide to leave because it has become a rip-off in a year or two, I'll still have to go back to some self-hosted solution and extract the data from your page somehow.

There's an app called Baby Connect to do same things, but for human babies. Among the ones we tried, we liked it the most. It includes ability to add another person, and then it syncs data with them (the feature i liked most). Perhaps that app might serve a good set of inspirations.

I can also imagine creating PDF report between user-given dates that people might need when visiting vet, or emailing them.

Neat idea. Agree with the below suggestion for screenshots. A video would also go a long way on the homepage for how to use.

Integrating google sign in might lower friction.

Small error in that there are no frequently asked questions in the FAQ section of https://waulog.com/guide#faq

Do you have some screenshots?