Need a co-marketing affiliate app

[jimdirect]

Hello.  We have a couple of companies who want to partner with us and sell their product on our site and ours on theirs (all have shopify). What is the best app for that. Thanks for the assist! 

We don't really need a full blown affiliate app.  Just something where we can build pages, share sales percentages and upsell/cross sell each others products.  Thanks!