Ab exercises at home

Abs:
Regular plank, wide legged plank, side plank (add leg lifts), left lifts, diagonal leg lifts, reverse crunches, crunches, the bicycle, twists with a dumbell, "spiderman" plank (start in a regular plank, lift one knee to your elbow, repeat other side).

You can work any muscle group at home not just abs;
Butt/legs: Squats, hip bridges, side lef lifts, donkey kicks, lunges, side lunges, calf raises, plie squats
Arms: push ups, tricep dips, arm circles and pulses, dumbell exercises