Sparrow Wallet's about page divides its credits into two lists. Under "Building" there is one entry, "@craigraw". Everyone else is under "Supporting", which is the donation list.
The download page identifies the same person by name. Each release ships with a signed manifest, and the verification instructions show the expected output: a good signature from "Craig Raw [email protected]", against a key published at keybase.io/craigraw. That signature is what a user checks before running the binary, which makes it the most load-bearing appearance of the name in the project.
Sparrow itself is Apache 2 licensed, has no company behind it that the project discloses, and is funded by donations. Its release binaries are reproducible from v1.5.0 onwards, so the claim that the published source produced the published binary is one a third party can test.