[yazan94]

I'm not super familiar with code signing, but if alternatives are expensive, could OP maintain a checksum value on their download page rather than go with DigiCert or alternative services? Or does code-signing solve a different problem?

[nishkalkashyap]

No. Code signing is very different. Checksum would only work for developers on linux. Without code signing certificate, MacOS would straight refuse to run the app and windows will show an 'Unverified publisher' warning. Also things like auto-updates do not work on either platform unless you code sign your binaries.