For the majority, developing iPhone applications doesn’t bring in the wealth that is dreamt of, however if you are one of the lucky ones, like iPhone app developer Tapulous, iPhone developing can mean big bucks.

Tapulous, the developer of iPhone games such as Tap Tap Revenge, and only employs 20 workers has now reported that their sales have now reached a staggering $1 million per month with their Tap Tap Revenge being installed in excess of 20 million times with more than 600 million games being played reports Reuters.

According to research group comScore earlier this year, they said that Tap Tap Revenge has been installed by 1/3 of iPhone application users. Tapulous now says they are profitable but decline to give exact figures.

Apple has sold more than 50 million iPhone handsets and iPod Touch units which uses the same software, and Tapulous generates revenue by charging for some games, through adverts and selling music through games.