This is one of the funniest newer Disney Channel shows I've seen since Gravity Falls. It has no annoying laugh track, has some pretty dark humor in it (surprising since it's main audience is middle school girls), and is just entertaining. So what's the plot?
Gabby is a middle school aged girl who is sort of ignored by her mom and younger sister. Her principal , whose name is Principal Principal Swift (because he's the principal of the school, and his first name is also Principal) sees something special in her, and reveals that he and his nephew Jeremy are aliens in disguise hiding out on Earth until Jeremy becomes old enough to become king of their planet. Gabby does such a good job babysitting Jeremy on her first day that Swift recommends her to other aliens who are hiding out on Earth. I will say, this is a pretty fun premise. Some of the aliens have very creative designs and powers. There's one alien who was clearly modeled after Eleven from Stranger Things. By far, the best characters on the show are Principal Swift and the Orb. Swift reminds me of Matt Smith's portrayal of the Doctor from Doctor Who, mixed with Dick Solomon from 3rd Rock from the Sun, particularly with the way he unintentionally makes people feel awkward with the way he misunderstands Earth culture. For example, there's an episode where he's teaching Jeremy about dining out, and based on his previous observations, gets the idea that humans always have to send back the first dish given to them. He annoys the waiter by doing this, and they get banned for life. It's like that one 3rd Rock episode where Dick Solomon adds or takes away from his waiter's tip pile based on how satisfied he is with his service. The dark humor in this show comes mostly from the Orb. She sort of reminds me of GLADOS from Portal. There's an episode where Jeremy is sick, and Earth doctors don't have a cure, so the Orb decides that they should let nature take it's course so she can get his room. Never thought I'd hear that on a Disney show, though I guess if Gravity Falls can have a villain say he's going to murder children, anything goes at this point. If you want a modern Disney show that entertains without some of the lower humor, than check out Gabby Duran and the Unsittables