Complete newbie needs some help (...sorry!)

Hello everybody.
I'm sorry to be a complete pain, but I have a few queries that I haven't been able to find answers to elsewhere.
Basically, I use the 4track app for my iPhone for recording quick ideas, mainly vocal arrangements and an acoustic rhythm and lead, rough ideas for choruses and so on. I found out about riffworks and so have downloaded it, and while I've been able to import the song ideas into RW so that they show up as 4 layers, I cannot for the life of me figure out how to add a beat or anything at all to these 4 layers. I can add effects, but when I save the file and re-open it, the layers are gone and need to be reloaded. There's obviously something simple I'm not comprehending, but my question is this; is it actually possible to import (for example) 3 or 4 tracks from my 4track app onto riffworks, to put a beat behind and and structure etc? Or do I need to have an interface and actually record tracks properly rather than import (in which case why does this feature exist in the first place..?). Apologies for the confusion, i'm sure you've seen this post a thousand times before, but a musician currently on a budget of £0 and am in dire need of a way of demoing ideas further than just an app on my phone.
Thank you in advance.