Thanks for your help!
Yes I knew about the BonBon offer, but I was hoping there would be something more interesting / cheaper to keep alive.
I see Vipme now also has a daily offer: 1GB for 10 Kuna. Now
PrePaidGSM: Croatia states that the validity is 6 moths + 6 months to recharge, but I cannot find this on the site of Vipme. Could you perhaps point me to it?
Also, how is the network coverage in Croatia? I will be travelling so a good network would be nice.