On average, the typical person opens up their phone 150 times per day, and this number can easily increase to 300, this means once every 5 minutes.
Cannot force yourself to use your phone less?
Maybe if money is involved in this equation you are going to be more motivated. Every time you open up the phone you are going to voluntarily pay 0.003$, not much, but in time it gathers.
Also, 50% of the money you are paying will go towards solving an environmental problem, it's a win-win.