For this short workout you need a ball (football sized) or a small cushion. This is a inner or 'deep' core workout and an inner thigh workout, utilising the connection between the two.
You can do this workout as a standalone or as an add on to another workout.
There are 4 exercises:
Hover with ball squeeze
Hover with rotation
Bridge with single leg raise
Leg extension and lowers
See this video for an instruction on each of the exercises and follow along: