My GPS is made by Garmin ... as well as pretty much every other commercial GPS product in the US. There are a few other smaller players.
If I drive around, my GPS gives me street by street and turn by turn directions ... I wonder if you can do this in Cebu ... or if the streets haven't been mapped yet. I don't know about Cebu or Manila, but from the website, it looks like Garmin has maps for Singapore and Malaysia. If you look at this and use the MapSource Map Viewer ... select World ...
Cartography
It doesn't look like Garmin has city maps of Cebu.