What are you expecting Yuda? How you coded the locationsensor to work (show an image of your Blocks please) and how frequently you tell the gps to try to provide a satellite fix might be the problem. How the LocationSensor works is described in Using the Location Sensor . There are two aia files you can load to test your GPS.
You said you 'create my app..viewing current location in leaflet js.; do you mean you use the MIT Map component or something else? The map tiles come from OpenStreetMap (OSM) . How rapidly they load on your device depend on their donated servers capabilities and your WIFI or network connections. Sometimes, the rendering is slow but usually quite fast.
You said 'not accurate lat and long'. Would you explain that please. The precision of the location provided by the GPS receiver depends on how many satellites is used in the satellite fix. The accuracy of the fix is influenced by many factors discussed in the above link. A modern cell phone GPS receiver can resolve a distance of 2 meters at best using the LocationSensor. It will provide about 10 meter or better resolution in most instances. Would you expain what is wrong with the latitude and longitude in your app? For reference, 0.00001 degrees of latitude represents about 1.11 meters at the equator
Have you discovered the LocationSensor and Map component documentation ( LocationSensor and Map components )?