Try socialadr and onlywire. Social bookmarks aren't that effective anymore. I would avoid them and focus on better link building methods like guest posting and high quality PBNs.

There are two types of bookmarking. One way shares to just your profiles and the other to your profiles and thousands of other peoples profiles. These are the top social media publishing services that bookmark to all your personal profiles

(These will just post to your personal bookmarking accounts:

Onlywire
Sendible
Hootsuite
IFTTT
Gremln


(To share to your personal bookmarking accounts and to other peoples profiles you need a social media syndication platform:

You can Google "social media syndication" to find a company that will publish to other people's bookmarking services. This type of bookmarking allows you to bookmark all your profiles plus to thousands of other peoples profiles.