Medical practice seeks practice management software

I am looking for practice management software for my small medical practice in southern Germany.

The software should meet the following requirements:

• Patient management for private patients only
• Prescription creation (optional access to relevant databases)
• Invoices, billing
• Optional laboratory, laboratory data
• If not available, then interested in a module or add-on financial accounting
• Desirable compatibility with smartphones and iPads
• Easy to use, user-friendly
• Does not need to be suitable for home office use
• Cost-effective
• Windows-compatible

One software workstation for two devices (desktop and laptop) is planned.