You can grab your latest .deb release for Pyfa, the EVE fitting assistant.

The latest releases are available under releases

On Debian systems, you can verify the integrity of the changes file by,

gpg --verify --keyring /usr/share/keyrings/debian-maintainers.gpg pyfa.changes

or if you are not using Debian, get the key from official Debian keyring server and verify,

gpg --keyserver keyring.debian.org --recv-keys AC8DFBD0
gpg --verify pyfa.changes

Then compare the SHA256 sum of the .deb file with the one in the .changes file.

No. Pyfa changes with Eve, not with Debian update cycles. It is best Pyfa remains outside of Debian.