Hmm, i think you can work with firewalled. Mine shows as firewalled. Have you configured your browser to use the localhost:4444 as http proxy?
If you have try to browse to the following addresses:
localhost:7657 (this is the i2p router webui and if it doesnt load then either i2p is not running or is in a broken state)
localhost:7657/i2psnark (i2psnark is built into java i2p and if the previous link loaded and this one doesnt then you dont have snark, which may simply be a limitation of androidl
http://notbob.i2p (i just picked an i2p site, this one is an index of multiple i2p sites. If it doesnt load but the first one does, then your router is not working properly or your browser is not configured properly)
localhost:7070 (if this loads then you have i2pd installed instead of the java version, i2pd is not built with snark)
I suggest you install i2p on a computer as all this stuff works out of the box