The User Interface and the resulting User Experience is the critical challenge towards creating a successful mobile application. The User Interface alone can make or break the success of an app. Having a great UI is a must for every mobile application.
From mobile UI elements, UI animations, material designs to wearable UI, these are 25 websites that have the best mobile UI collections and inspirations to help you create the best UI for your app.
01. UI Haus
A showcase of the best mobile app designs ever made. Very easy to scan and their organization system of the website is quite good, where they show only one screenshot page per app, but you can select that one to see many more on each apps own dedicated page. Top recommendation.

http://beta.uihaus.com/
02. Material Design
Material UI Designs from Dribble. This tag subsection of Dribble is a great place to find inspiration and watch for trends. With many contributors it is updated very regularly and is a top daily choice.

https://dribbble.com/tags/material_design
03. UI Movement
One of the best UI design inspiration site. It is very easy to use and is updated regularly with member submissions. Includes many animation experiments for both mobile and desktop views but also good for viewing different layout concepts.

https://uimovement.com/
04. Pttrns
Design resources and inspirations from Pttrns is a splendid view for ideas and inspiration with many subcategory tags and Android and iOS specific areas. Very good usability and viewing and regularly updated, a top recommendation.

http://pttrns.com/
05. Sketchrepo
Inspirations from Desktop, Mockups, Icons, Mobile UI Kits, and Website Designs. Intended to be used for the Sketch program and often including downloadable templates. Has useful categories for mobile UI development and web development also. Easy to use website is a top recommendation.

https://sketchrepo.com/
06. Collect UI
Daily inspiration collected from UI archive and beyond. Very big selection with a broad scope and a lot of filter tags. Includes general design ideas in addition to mobile UI and mobile page ideas. A great resource.

http://collectui.com/designs
07. Grafi
Full screen tiled layout gets a lot of ideas in view. Good for both UI and overall design and styling ideas, the selection includes both existing app screenshots and icons, elements and animation concepts.

http://grafi.kr/
08. Mobile App Design UI
Mobile app design collection by Marine Sergent from Behance. He has good taste so a scan through this collection is time well spent for mobile UI inspiration.

https://www.behance.net/collection/3942497/Mobile-App-Design-UI
09. Lovely UI
A collection of lovely UI elements. The selection is pretty modern, mostly minimalistic app designs which is a good target. Has a good Tumblr layout and easy scanability, is regularly updated and good for a quick glance at least.

http://www.lovelyui.com/
10. Laudable Apps
Mobile UI inspirations shown with very large screenshots, which in this case is a surprisingly welcome view. The pages load quickly so it is a good scanning experience. No filters, however the selection is generally inspiring.

http://laudableapps.com/
11. Materialup
Mobile Material Designs from Uplabs. Mainly includes user interface and elements animations, experiments and proofs of concept. Website is ok to use but not always completely intuitive or user friendly. Is updated frequently.

http://www.materialup.com/
12. Androidniceties
Collection of screenshots from some of the most beautiful Android apps. This one has one of the best layouts for gathering ideas as the entries have several screenshots across the page and are easy to scan downwards. Includes major apps and some lesser known ones so is definitely worth a look. The images aren't gifs so the pages load more quickly and are easier to scan for UI ideas.

http://androidniceties.tumblr.com/
13. Android App Patterns
Over 1700 screenshots of UI designs for inspiration. Similar to Android Niceties this site has multiple screeshots of apps pages side by side and they are not gifs so scanning for mobile UI inspiration is easy. Many filter tag sections help find relevant ideas quickly. Unfortunately has not been updated for a long time but still worth a look.

http://www.android-app-patterns.com/
14. Androidpatterns
Set of interaction patterns that can help you design Android apps. A helpful compendium of the UI ingredients and cornerstone concepts required in a mobile app. Has not been updated recently enough but still worth a look when at the wireframing stages.

http://unitid.nl/androidpatterns/
15. Android Experiments
Collection of creative application ideas that inspires you to create great design or even a new app. This collection focuses on creative, real world, in-production experiments and apps that are taking Android beyond what we think of normal applications. Think phones used as wireless controllers, virtual reality connections, interactive body input methods - if it's outside of the box thinking it's here.

https://www.androidexperiments.com/
16. Mobile Patterns
List of UI design screenshots that are very easy to scan. The selection is OK and worth a look.

http://www.mobile-patterns.com/
17. Inspired UI
Mostly iPhone UI screenshots but also Android. The screenshots are huge and not overly organized so scanning for ideas takes a lot of scrolling but it is worth a look. Has a decent collection and useful categories.

http://inspired-ui.com/
18. Android UX
Small but awesome collection of Android UI elements. The selection is not extensive but it is a good quick look at different patterns categories and elements for app's pages. It is all screenshots and not gifs so at least it is fast.

http://androidux.com/
19. Games Inspiration
Mobile game designs inspiration for mobile game developers. Big selection and specific filtering system empowers good viewing for game layout and features ideas. Definitely worth a look for games developers.

http://gamesinspiration.com/
20. Wear UI
A nice collection of user interface designs for wearable devices. Good layout and ideas may help with ideas beyond wearables as well.

http://wearui.co/
21. Uplabs
The root website connected to MaterialUP, has a good variety more also spanning to desktop views but the mobile UI ideas abound here as well.

http://www.uplabs.com/
22. Mobile UI List
A list of UI designs with almost 100k followers from Pinterest. Great selection and variety but requires logging in to Pinterest unless you would rather play whack a mole deleting their obtrusive signup and login pop ups.

https://www.pinterest.com/timoa/mobile-ui-list/
23. Heyuser
A Video Gallery for Mobile Onboarding Design Inspiration. This is a hot stop if you are working on an onboarding strategy and presentation. Great selection and good layout, is also OK for general mobile designing ideas.

http://www.elasticode.com/HeyUserIndex.php
24. Theultralinx
A good Tumblr blog showing some nice mobile designs and UI concepts and patterns. A lot of conceptual shots which is good if looking for 'presentation of the app' ideas as well.

http://ui.theultralinx.com/
25. My Color Screen
Large collection of mobile designs for iOS and Android. A bit of a stylistic mishmash, and its focus is on homescreens or pics, but there is a lot of material covered in this big collection.

http://mycolorscreen.com/
We hope this list of best resources for Mobile UI inspiration and design has been useful.