LEDs on GPS can tell you some, but they do not have all the information. They do not know about PDOP for instance.
The LEDs (orange and blue if I recall correctly) on the FC go from long orange, long blue when it is not ready to arm to long orange short blue when it is ready to arm and then to short and short after you have armed it.
You can also add WS2811 / WS2812 LEDs (search wiki) for something brighter and to mount where it is easy to see.