G1? 1.6... DONUT!!!!!
makakahanap ka pa apps for it pero not that much considering its an OLD OS, most apps nowadays require 2.1 Eclair pero you can still try, just go to Market and install the stuff you want basta naka connect ka sa internet, you can also root it and install apps from the Root market(aka the pirates market)
*note android OS are named after pastries/desserts/sweets
1.6 Donut
2.1 Ecliar
2.2 FroYo(frozen yogurt)
2.3 Gngerbread
2.4 di ako sure if meron nga
3.0 Honeycomb (requires Tegra 2 for tablets, a better CPU for smartphones)
DROID!!!