Personalisation for Add on Items (Cross Selling)

[blueskies]

We sell a range of personalised items e.g. pet blankets and we have an app which let the customer add their pet's name before they add the blanket to cart.  This works great.  The problem is that we want to cross-sell other personalised items eg hoodies.   We can't find an app which allow the customer to add an additional item AND enter their wording before purchase.  Has anyone else had this issue and managed to resolve it? 

I guess we need a personalisation app which is compatible with a cross-selling app.