Rental Channel Manager App

I need an Android-based channel manager that pulls my existing listings from Airbnb, Vrbo and Expedia into a single interface and keeps everything perfectly aligned. The core of the build is a reliable two-way calendar sync so any change on one platform instantly reflects on the others and inside the app. Alongside that, I want to confirm and modify reservations, block dates, and adjust nightly rates without having to open each marketplace individually.

The app should:
• Maintain two-way synchronization of availability, reservations and modifications.
• Let me review, add or cancel bookings and automatically release inventory everywhere.
• Push rate changes from the app to all connected channels in real time.

When a new booking comes in or an existing one changes, I expect both a push notification on the phone and an email summary so I never miss an update. A clean, lightweight Material-style UI is enough—no extra bells and whistles beyond what keeps workflows fast.

Please build with future extensibility in mind (additional channels, rules-based pricing, etc.) and deliver a fully functional APK plus source so I can upload to my own Google Play console if I choose.