Gmail added very important improvement to its service, one of the most wanted by its users. We can now add logos to our email signature and format the text as we want.
Gmail used to support plain text signatures, now we are able to add company logos, fancy formatting, website and email links etc.
However, only the latest desktop version of Gmail supports rich-text signatures. Older versions of Gmail, which use the simplified HTML version, and mobile Gmail, will still use plain text signatures.