I could also see LEM for Lunar Excursion Module, the technical name of the lunar lander during the Apollo missions (a nice nod to Apollo app). Also has the benefit of being similar to Lemmy.
Voyager is the name of the default testing instance for the Lemmy project AFAIK. Having two things in the Lemmy-verse called Voyager will be confusing.
Wefwef is nice for SEO and unique, so i don’t mind it, but like you said—i don’t know how to pronounce it.
My suggestion would be “Mooshuck”. Sounds fun, is easy to pronounce, doesn’t have any well-known project with that spelling, and means “little mouse” in Sanskrit. This would be keeping in line with Lemmy and Jerboa which are little rodents.