Is there an IC that works like the PL2303 for TTL TO USB?
Why can't you simply use the PL2303? it's still manufactured and quite available AFAIK.
Another hugely popolar USB/TTL serial bridge it the FTDI  FT232 (many different versions, also bootlegged ones)
As for the Android support you could look at https://github.com/mik3y/usb-serial-for-android, it should handle many chips (included the PL2303)