FULL GUIDE ON USING JUST ANDROID PHONE. NO PHYSICAL COINS/CARDS. I screen recorded this bc I'm sure it'll be removed from YouTube soon. Credits to 8bitbish! : r/Amiibomb
Amazon.com : 20pcs TimesKey NFC Sticker NTAG 213 Fully Programmable NTAG213 NFC Tags Circular Stickers, 144 Bytes Memory Compatible with Android and Other NFC Enabled Devices : Office Products
Is it possible to use a trio of real Mii Fighter amiibos and a hacked Android phone to circumvent Smash Ultimate's mii fighter limit? : r/Amiibomb