“Grown-ish” may be a spinoff of “Black-ish,” but its closest relative is “A Different World,” although I don’t remember Denise dealing with a gay roommate and drug addiction. The show deals with even more mature topics as it launches its second season, but Minnesotan Yara Shahidi leads the cast with a light touch. As a comic actress, she continues growing more confident.
7 p.m., Freeform
Who you gonna call?
“Mythbusters Jr.,” an offshoot of the popular science series that has kids taking on the bulk of the lab work, is a noble idea. But the premiere, which incorporates the many uses of duct tape, keeps getting interrupted by grown-up Adam Savage, who is way too interested in looking back at old clips from the original show. These youngsters, including South Dakota’s Allie Weber, are too smart — and too interesting — to have so much adult supervision.
8 p.m., Science Channel
Hiding in plain sight
In “The Masked Singer,” supposedly famous figures perform while wearing costumes lifted from mascots for an S&M club’s flag football league. Jenny McCarthy and Nicole Scherzinger are among the panelists trying to figure out who’s under the costumes — and what happened to their own once-thriving careers.
8 p.m., KMSP, Ch. 9