There are several ways of producing this reaction:

Hydrogen peroxide (30%) + KMNO4 (potassium permangate)

Hydrogen peroxide (30%) + NaOH (Sodium hydroxide, usually found in drain cleaner)

Hydrogen peroxide (30%) + chopped liver (contains the enzyme catalaze)

All of the above reactions catalyze hydrogen peroxide to water and oxygen. The blue liquid in the jar is soap, making foam as the gas develops.

The reaction can be quite dangerous as hot steam, hydrogen peroxide & the catalyst come shooting up very fast, so i wouldn't recommend trying this without proper supervision and safety equipment.