I will say that I was initially a bit confused by the web page; it took me a minute of looking around for a register/login link, for sample guides, or for the community boards... before I realized that the web page is just a brochure for the mobile apps and a place to link your 'gram. I prefer to consume long-form content on my PC rather than my phone, so that was a bit of a disappointment.
On downloading the Android app, I was greeted with this error message:
https://i.imgur.com/gi0MfZz.png
Hopefully that's just HN's Dad hug of doom (I'm on solid wifi and have a great network connection; it's almost certainly not on my end as the message implies).
Starting to page through the app now; looks like you have lots of content! I'll let you know when I have more time to really dig into a few articles and the features.
Another place I go to for Dadditude-like conversations is https://www.reddit.com/r/daddit. We do have a very limited policy for self-promotion, see https://www.reddit.com/r/daddit/wiki/blogs for details (or message the mods), in particular self-promotion should be <<10% of your content. But if you are already a redditor who wants to help fathers you're probably already there, encouraging and commiserating with us over people who call dads parenting 'babysitting', cleaning up the messes of our kids, and trying to be better dads...
PS: I'll echo and slightly disagree with the sibling commenter who was distracted by the first paragraph of your pitch: "Being a dad is a long, emotional, draining, and lonely journey. Through our research we learned that dads want to improve their parenting but are too shy to ask for help, and are tired of reading content online written for mums. We set out to fix that and create a platform that would help dads feel seen, validated, and supported."
Wow, that's a depressing framing to everything that follows. Try something more positive, and be willing to qualify it with some weasel words where you have to: Being a Dad should be an rewarding, amazing, fulfilling, awesome journey, that has commensurately high challenges and requirements, and it can sometimes feel draining or lonely. Asking for help is hard, and it's difficult to find quality, precise help when you do ask. We want to help dads be the best Dads they can be, recognize the work they're putting in, and support them in the important role they have in their families.
Good luck!