I have to compare the impact of incentives on an App users (If they avoid using cell phone while driving). The variable is discrete (Number of time they use phone while driving). The first sample is users in Jan-Feb without incentive (smaller in size) and the second sample is users in March with incentive. As some users from Jan-Feb are using the app in March, I cannot use the Chi Square test. I guess I can use rAnova if only the people common in Jan-Feb and March are analyzed.

What should I use if I want to use all the samples and compare between them?

Thanks in advance