Yes, the Openprovider email solution is compatible with mobile devices.
Configure your device's email app with the following settings,
IMAP settings:
Incoming Server: mail.op-email.eu
Port: 993
SSL: Yes
SMTP settings:
Server: mail.op-email.eu
Port: 587 (STARTTLS) [RECOMMENDED] or 465 (SSL/TLS) or 25 (non-SSL, though often blocked)