I can find many of them in the communication category.
And I try many of them, I found that my favourite add-ons are
Google Translate, it really works well on my cellphone.
Speed Dial, convenient and useful.
Adblocker, work well but need improvement.
Screen Cut, I also like
Bing Search, YouTube search...convenient in search
Desktop Toggles, Compact page toggles.. one click to switch!
Show IP, WhoIs, Alexa Ranking, .. not that useful for me, maybe geek user like them.
I had arranged the new add-ons in Dolphin's add-on wave in July.
just for your information, hope you like my post.
compact page toggles