I just have a look at messaging app development like whatsapp. It takes 1800 - 2300 hours with team of 5-6 devs, so approximately 4 months.

https://djangostars.com/blog/how-much-does-it-cost-to-build-a-messaging-app-like-whatsapp/

In our case, we know they are 2 devs so it could take 1 year to have a product.

Nevertheless, I agree it don't explain the lake of communication...