What it is. Cards marketed to "bad credit" that approve almost anyone — First PREMIER, FIT, Surge, Reflex, Indigo, and similar.
Why it's risky. Stacked setup, annual, and monthly fees can swallow most of a tiny limit, so you pay a lot to build a little — and a small limit you carry a balance on hurts your utilization.
What to do instead. A $0-fee secured card that reports to all three bureaus (Course 2 · L4) does the same job without the fees.