Hello Bar offers this feature and it has been very useful to test what language and words work better. Also, to test what converts better. Sadly they don’t offer a Hubspot integration so my team had to build one. Also, it is not possible to target based on lifecycle stage since Hello Bar does not have the data.
It would be most optimum if Hubspot gave the A/B testing feature + some of the other features of Hello Bar. Till then Hello Bar is a good alternative. Here is my affiliate link of Hello Bar in case someone wants to register and get a free account: Click here to get a FREE account of Hello Bar
P.S. I am not sure if Hubspot rules allow sharing affiliate links. Please let me know if I should take it off. Though, I would still recommend it as an alternative to Hubspot Popups till A/B testing and other features are available.