"Something Wonderful" is the platform that shark Kevin O'Leary (known to almost everyone who watches the show as "Mr. Wonderful") created to tie various companies that he has invested in together to maximize their synergies.
While this sounds like typical corporate speak, what it really means is that some businesses might share customer demographics and even specific customers at certain times and that a customer who needs wedding services today might need baby cards tomorrow.
To this end, Kevin has grouped a few of his companies into what he refers to on the show as the Something Wonderful platform. The idea is that companies that are a part of this platform can share customer lists and strategies and drive sales from one business to the other as the occasion demands.
As far as can be found on public sources  the companies on the Something Wonderful platform include:
Wicked Good Cupcakes
Bottle Breacher was a company that Kevin invested in on the 7th episode of Season Six along with Mark Cuban and specialized in making bottle openers from spent ammo shell casings. It was started by a military veteran and his wife and they not only made bottle openers that could be kept in one's pocket but shiny, special, engraved versions as well.
Honeyfund was a "crowdsourcing platform" designed for couples about to get married who didn't want to do the normal registry of gifts. Instead, they would rather have guests give money for a specific purpose (generally a honeymoon). Kevin invested in Honeyfund in the 5th episode of Season Six.
- The most reliable source found on the platform was from PR Web], a site that publishes press releases issued by businesses themselves.