If you go to a park with a bench, this exercise is nice for legs
Stand on the bench with one foot on it, and one foot free in the air to the side. Not too far... bit close to the bench. now squat down with that one leg... don't lose your balance, just go as far as you can, then come up. Do 15 reps per foot.
If you've got a lower bench you can also do jump squats. You jump onto the bench and assume a squat position, hold it for 5-10 seconds (depending on how strong you are), then jump off then jump right back on and repeat 10-ish times.
These aren't the best for size but they're quite good for endurance and power.
Stand on the bench with one foot on it, and one foot free in the air to the side. Not too far... bit close to the bench. now squat down with that one leg... don't lose your balance, just go as far as you can, then come up. Do 15 reps per foot.
If you've got a lower bench you can also do jump squats. You jump onto the bench and assume a squat position, hold it for 5-10 seconds (depending on how strong you are), then jump off then jump right back on and repeat 10-ish times.
These aren't the best for size but they're quite good for endurance and power.