You're essentially dealing with what sounds like an active equity investor. Have you put in any money yourself? What would you consider your "good will" and "sweat equity" to be? A 50/50 split seems decent.
Technically speaking you should form a new LLC and split ownership of the company, and then all revenue coming into the company would directly flow through to you two (the owners/members of the LLC), since LLCs are pass-through entities.
Good Will: What you bring to the table in experience, and your ability/desire to keep the project on track and be completed.
Sweat Equity: Sweat equity is a party's contribution to a project in the form of effort -- as opposed to financial equity, which is a contribution in the form of capital. In a partnership, some partners may contribute to the firm only capital and others only sweat equity.
If you find your good will and sweat equity are valued at more than $25,000, you may be able to lay claim to more than 50%.