I responded to your ticket. I'm fairly sure Core mobile runs only a lite wallet, so it's to be expected it doesn't support arbitrary utxo lookups.
Sry, my knowledge is very limited.
However I'm quite sure the Bitcoin-Wallet was able to sweep paperwallets (from bitcoinpaperwallets.com). I'm positive cause I tested it first to try if the paperwallets would actually work (I had never tried them back there).
Thank you very much for your answer.