Location-based Services in buildings represent a great advantage for people to search places, products or people. In our paper we examine the feasibility of Bluetooth iBeacons for indoor localization. In the first part we define and evaluate the iBeacon technology through different experiments. In the second part our solution application is described. Our system is able to estimate the position of the user's smartphone based on RSSI measurements. Therefore we used the built-in smartphone sensor and a building map with required sender information. Trilateration is used as positioning technique in contrast to fingerprinting to minimize beforehand effort. Results are promising but cannot reach the same accuracy level as sensor-fusion or fingerprinting approaches.