The tower generates money on its own. Click the tower to make more money. Pretty straightforward.
Update Log: 1.1.2 - Added some music I made in FL Studio. 1.1.1 - Fixed a bunch of bugs. 1.1 - Reworked the save/load system. Added an immediate buy button to quick-buy floors. Floor cap raised from 999 to 9999. 1.0.2 - Fixed incorrect pricing on the Tenant Boosts. 1.0.1 - This time REALLY fixed going into debt. Also squashed a few more minor bugs. 1.0 - Fixed going into debt when buying an upgrade too early. 1.0 Beta - A tower with 999 floors, save codes, and upgrades. Not too bad for a beta.