Hi @bksubhuti,
There are three Flutter apps that I helped bring to Flathub — Feeel, Parlera, and Time Cop. You can take a look at the manifests for those; Feeel uses SQlite for now, so it’s particularly relevant.
The idea is to pre-compile the app and then just ship binaries as part of the Flatpak.
I built each of those Flatpaks manually. However, I am working on automating builds through Github Actions. The first project that I’m building this way is Parlera — see:
I’m automating it to the point of creating the x86_64 Github release. Then I manually still upload the ARM builds and the Flathub manifest file. However, if you forgo the ARM builds (or if you pay extra for Linux ARM VMs on Github), the Flathub manifest could also be automated away — see wger for inspiration for that.
This automation is a brand new for me, and I’m currently getting stuck at the “Check for AppStream XML” step for some reason. I’m doubtful that the automation is at fault here, though.
I know this was a mouthful, so let me know if you have specific questions that I could help with.