Wallpaper Mobile App Development

Hi,

I am looking for an experienced mobile app developer to build a **Wallpaper App** for Android (and iOS if possible). The app should be modern, fast, and user-friendly with a clean UI.

**Requirements:**

* Large collection of HD & 4K wallpapers (categories like nature, cars, anime, etc.)
* Easy browsing with search and category filters
* One-click download and “set as wallpaper” feature
* Favorite/save option for users
* Admin panel or backend to upload and manage wallpapers
* Push notifications for new wallpapers
* Ad integration (Google AdMob or similar)
* Smooth performance and fast loading

**Optional (Bonus):**

* User login/signup
* Dark mode
* API integration for auto wallpaper updates

I want a complete solution including design, development, and deployment on the Play Store (and App Store if applicable).

Please share:

* Your previous app work (especially similar apps)
* Estimated time and cost
* Technologies you will use

Looking for someone reliable for long-term work as well.

Thank you