Unfornatelly, Mifare Classic technology is not compatible with all devices.
Some Android devices read some basic information like UID but cannot read or write data.
On iPhones, this tech is not fully compatible yet and you have to enable the "compatibility" mode in NFC Tools settings.
If you need compatible chips, we suggest to get this reference: NXP NTAG21x (NTAG213 or NTAG216).
