Yes as long as they're different! To be clear, you must submit working software and not just an idea.
The rules state, "Multiple Submissions: An Entrant may submit more than one Entry, however, each Entry must be unique and substantially different from each of the Entrant’s other Entries, as determined by the Sponsor and/or the Administrator."
You can definitely submit multiple projects, however: If an individual, Team, or Organization submits multiple Entries, only one submission may win, and will be the highest-value prize for which they qualify, or whichever prize Sponsor chooses if the prizes have the same value.
So submitting multiple ideas would increase your chances of winning a prize, but you would only be awarded the highest prize that your submissions earned.