Just the openssl version is not enough, since it could be patched to fix vulnerabilities without increasing the version (this is very common on Linux distributions, which often apply security patches instead of migrating to a new version; for instance, Fedora released a patched 3.0.5 instead of going to 3.0.7).
And using an older openssl version does not necessarily mean it's using vulnerable code; according to your blog post, the most common use is SQLCipher, which from a quick look at its README.md seems to use openssl only for the encryption algorithms. Unless the vulnerability was on the basic algorithms used (AES, HMAC, etc), it won't affect this usage.