Nowadays, tourist don't use services off travel agencies as much as they used to, instead they use Internet to reserve desired services related to the process of traveling to a wanted destination. Mobile application development has enabled quick and easy access to book accommodation and flights. Mobile guides make virtual world in which tourists can explore places interesting to them in multiple places, also other participants who are involved in tourism can present their products and services via mobile guides. Mobile guides in the county of Istra are an excellent marketing tool for promoting destinations because they provide plenty of information to tourists. Also, by using mobile guides, tourism participants can find out what needs to be changed in the existing offer so they can satisfy tourists preferences. In the county of Istra, there are a lot of mobile guides, but only few of them record a large number of downloads. Although there are numerous of mobile applications all around the world, we can safely state that croatian mobile applications are not represented in large extent. There are many reasons why is it so. One of the most important reason is fact that the most of the mobile guides have similar content and very small number of croatian mobile guides differ from each other. Therefore, tourism companies should focus on further developing of mobile guides and applications and such development should lay the basis on the quality of content and additional, interesting informations. As a tourist country, Croatia should make much more effort in developing mobile applications for tourists, a well as making them available to tourists. Keywords: