The Singapore Airlines A380 seating map has First Class in the nose, sold as "a class beyond First" with individual cabins and double beds in the two middle cabins. Middle suites are slightly longer than the side.
The seat plan for Economy Class in the Singapore A380 has a generous seat pitch of 32” and a crowded 3-4-3 layout on the lower deck. Due to the curvature of the hull, window seats here have restricted legroom. Much better is the upper economy deck, where the small A380 rear cabin has a cosy and quiet 2-4-2 layout.