https://www.digitalocean.com/products/app-platform
Railway.app is pretty nice, very slick interface, this has the most "heroku-feel" -
It's been solid since I got up and running but took me about a day to get a simple CRUD app moved over to it.
If they can improve the documentation it'll be much better. Right now I'm not considering it for future projects though just because platforms like Fly.io and Render seem to have better docs and additional functionality that DO Apps doesn't have yet.
^ Note: I use to work for Aptible. Great company. Great people. Now working for one of their spin outs.
Lots of awesome products here, I'd argue that only replit is a true 10x change from the Heroku innovations in terms of providing a next-gen developer experience.
I'm the cofounder of a new company called Coherence, that we think creates a new direction and offers a better platform for the next leap forward. By integrating from dev to prod and capturing the whole SDLC, as well as by operating in your own cloud, we're focused on delivering the best developer experience possible, without compromising anywhere else. Check us out at https://www.withcoherence.com. We're in an early closed beta so not yet a fit for all teams, but feedback is welcome!