So what are some differences between blu and volcano? Kind of confused if they are made by the same company. Is it just a different logo?
It's not the same company, it's the same model (L88b). Well, the same manufacturer, if that's what you mean... but re-branded by two completely different companies. This is very common in the e-cig industry... e.g. the 510 model is branded as the Dura, the Titan, and the Yeti; the KR808D-1 model is branded as the Vapor King and the Nebula; etc.
Anyway, the differences between the Blu and Volcano:
(1) The Blu has a blue LED; the Volcano has an orange LED
(2) The Blu battery is smooth; the Volcano battery has a subtle ribbed look to it
(3) Blu cartridges come in "natural" (tan filter) and black (except for menthol, which comes in white or black); Volcano cartridges come in white or black
That's about it. Volcano also offers one additional flavor: Pineapple. Volcano also seems to be more progressive on adding new accessories... e.g. they offer disposables, a car adapter, and their USB passthrough should be available next week. But since it is the same model, you could obviously buy Blu batteries and whatnot from Blu and buy additional accessories from Volcano.
The prices are also different. Volcano cartridges are cheaper, and unlike Blu, they don't make you buy a carton (5 packs) at a time.
Consumer feedback would also suggest that Volcano has faster shipping times, and better overall customer service. They also have their own forum.