Tucano is not the best of the Winboard/Xboard engines compiled for Android, especially when compared to ExChess, Scorpio and Crafty but it's one of the significant engines.
The updated version 6.00, compiled for Android by Jim Ablett, is expected to replace 5.00 which is currently rated ~2650 ELO in Rapidroid and add some more ELOs.
As i'm just finalizing a new list for March-2015, the new Tucano will have to wait for April to show up.
Let me remind that v5.00 can only work with Chess for Android and only with fixed time per move setting. I don't know yet whether v6.00 will handle Fischer clock.
Download Tucano 6.00 for arm5: HERE
Download Tucano 6.00 for arm7: HERE