How To Split Ad Revenue?

I have a friend that likes development. I was thinking of doing a mobile app project together… but I see all sorts of issues with how to split any income. How would you split ad income? How would taxes work? Is this a bad idea or is there an easy way to both work on an app together?

You could split revenues after they are earned, or you do it on the code side. The main thing is to decide on the split from day 1 and get it in writing, so that there can be no issues in the future.
Regarding tax etc, that depends on what country you live in (and their country too if they live somewhere else). There should be plenty of resources for how you could get set up with the laws of your country.

If you want to seriously work together, you both have to be committed, honest and to get the official terms in writing.