Beyond Flat is well worth a read. It looks at the various difference and similarities between iOS and Android - excellent when doing cross platform work.

Creating apps for both platforms is difficult; I have huge respect for the companies that nail it. Nailing it means not taking a reductionist approach (“we killed the gradients and shadows…so we’re good to go!”) but instead being intimately familiar with the platform so that you can build something that feels meant to be there.