Jasco is the actual manufacturer.
Enbrighten is the name they themselves use for devices sold at retail.
Originally, Jasco licensed the GE name, so that consumers would feel better about their devices. GE does that quite a bit, actually. They let other companies use their name and logo for a fee.
Honeywell has a reverse agreement: they wanted to have Honeywell-branded smart switches, and they went to Jasco and made an arrangement for them to build the switches. The difference between this and the GE arrangement is that Honeywell makes the agreements with retailers to carry their devices, while Jasco makes the agreement with retailers to carry the GE branded devices that they make.
The GE and Honeywell branded devices have nearly identical hardware, but the firmware, and therefore some of the features, are different.
Ultrapro has a weird history. It was originally trademarked by Jasco for television accessories, like cables and antennas. Then they started using it in combination with the GE logo for a slightly more expensive version of their basic GE Zwave products, typically sold in contractor packs of four or more.
Now I’m not sure what they’re doing with it.
So basically, all of these brands are slight variation of the same basic devices, which are manufactured by Jasco.
A common Practice
This is a common practice in the home-improvement industry. Many of the items that you see at Home Depot are sold under three or four different brand names. It may be a case of a particular brand name helping improve sales to a particular market, of wanting to distinguish between contractor channels and retailer channels, of providing a retailer like Lowes or Walmart with an “exclusive“ brand, which is really just re-packaging, or of providing packaging which meets specific regulatory requirements for certain purposes or regions. For example, something as simple as an extension cord sold for use in hospitals, may have special packaging requirements, and this might be met under a different brand name.
As far as devices that work with smartthings, another Z wave company that does the same thing is Nortek. Nortek, Linear, GoControl, Nutone, 2gig, and a couple of others might just be re-branded versions of the same device, put in a different box.