Guesthouse seeks reservation program

I am looking for a reservation program for my guesthouse (approx. 15 rooms). I have taken over my parents' business and until now we have always entered reservations by hand in a room occupancy plan. Correspondence was then created separately. A guest database exists only in the form of index cards.

The solution should support the following requirements:

• Room occupancy plan
• Simple guest database
• Process reservation requests from the program (email and mobile)
• Invoicing
• Interface option for future online bookability (HRS, booking.com, own booking engine)
• Functionality also on tablet or smartphone (Android planned)
• Windows-compatible
• Cost-effective

Some of these points are “nice-to-have” features, where the cost-benefit ratio plays a decisive role.

One software workstation is planned.