Developing Android App for Billions

Talk on "Developing Android application for Billions" delivered in DevFest Pune 2016 and DevFest Baroda 2016.

This deck is having android best practices to be followed and keep in mind while developing android applications.

1. Developing Android App for Billions Paresh Mayani @pareshmayani
2. AboutMe.apk Paresh Mayani Founder/Organizer, GDG Ahmedabad Technical Lead @ Lets Nurture Application Architect
3. Emerging markets will be at the forefront of smartphone growth 80% of smartphone growth till 2019 Source : GSMA Intelligence
4. 2016 2018 2019 Make your app work well regardless of how people are connected 2017 2020 47% 42% 37% 33% 29% 32% 32% 33% 34% 36% 21% 26% 29% 33% 36% Source : GSMA Intelligence 3G 4G 2G Share of mobile connections worldwide 100% 80% 60% 40% 20% 0% 1 Billion users will still be on 2G in 2020 1 Billion users will still be on 2G in 2020
5. Tailor your app experience to variations in mobile speed and connection quality Source : State of the Internet Report, Q4 2015 (Akamai) 15 UK KOR JPN IND ARG 30 22.5 7.5 Mobile Connectivity 0 AUS CHN IDN ZAF EGY SAU BRA CHL 50% 100% 75% 25% 0% VNM VEN % Above 4Mbps AVG Mbps
6. Good news: 4G is getting rolled out in India
7. But but it would take some time to reach to rural areas.... Source : Giphy.com
8. Help your users manage their data cost 3% AUS UK KOR EGY NGA 6% 4.5% 1.5% Post paid data prices (% of per capita GNI) Post paid data prices (% of per capita GNI) 0% Source : Measuring the Information Society Report 2015 (ITU) 4% 8% 6% 2% 0% HK CHN TH IDN MEX VNM IND BRA NOR HK UK NGA VNM AUS IDN BRA PHL IND EGY MEX KEN
9. Active Android Users 1.4 Billion
10. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
11. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
12. Prioritize traffic - text first De-duplicate network requests Adjust behavior by connection (For example, Youtube) Effective API Design (Avoid Select * ) Optimize networking
13. Load and Display TEXTUAL data first Load Images asynchronously Prioritize Traffic - Text First Note: Following this would help you in making your users busy in app, and meanwhile you load the data
14. Effective API Design At that moment when API developer writes “Select * from table” query and returns all the data in response
15. Send only required fields and avoid unnecessary details Most of the time enemy is Select * query Can optimize APIs with “Expiry date” or “Last updated” date Effective API Design
16. Optimize images Use Vector Images Serve dynamic image sizes No need to different sets of colored images, apply color filters Placeholder or low-resolution thumbnails can improve user experience
17. ImageView is 120x120 and image resolution is 1024x768 Purely injustice Image should be downscaled. Use some popular libraries like Glide. They provide caching mechanism, downscaling, thumbnailing, transformations, and what not. Serve dynamic image sizes
18. Load only Required size Cache Images Use Image loading libraries like Picasso, Glide, Fresco Serve dynamic image sizes
19. Note: Not a performance tip but a good practice in displaying UI Picasso library provides functionality to prioritize the image loading through priority(). priority() takes one of three constants, HIGH, MEDIUM, or LOW Load Images Priority wise
20. Useful Offline Experience Cache Image loading library
21. Because you know Internet sucks :) and Seeing “Loading…” dialog is boring Caching Data
22. Make your user’s busy Important: Display whatever data you have, meanwhile fetch required data Caching Data
23. Effective cache controls will dramatically reduce server load Cache data as much as possible, why? Less number of web requests => No use of network radio => Improved battery life Important: It will make user busy in reading something while loading new set of data Important: Don’t assume everyone has high speed connection in the world! Caching Data
24. Useful Offline Experience Test in airplane mode
25. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
26. Screen Sizes Test with emulator configurations Build for small & medium screens Optimize for mdpi & hdpi Test with emulator configurations
27. Efficient Memory Usage Adjust footprint by available RAM ActivityManager.isLowRamDevice() ActivityManager.getMemoryClass() Avoid long-running processes
28. Memory Usage Android Studio memory monitor 512MB RAM 1GB RAM 12.51MB 36.39MB
29. Smart Storage Use Bounded caches Cache in getCacheDir() Allow install to SD card Measure via app settings
30. Backwards Compatibility targetSdkVersion 23 minSdkVersion 15 Android Support libraries Google Play services
31. 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce Developing for Billions Framework
32. Those big and bloated Apks...
33. Those big and bloated Apks... Remember everyone doesn’t have super fast network?
34. Those big and bloated Apks... Remember everyone doesn’t have super fast network? Then show me ways to Reduce Apk size?
35. APK Size Images are biggest offenders Reduce code size, use ProGuard Set following in build.gradle minifyEnabled=true shrinkResources=true Multi-APK as an option
36. Inspect Code...
37. Inspect Code... Remove unused resources Optimized code Improve performance
38. Analyze Apk
39. Analyze Apk
40. Analyze Apk To avoid 64K referenced method limit issues with your Dex files Diagnose ProGuard configuration issues View merged AndroidManifest.xml file inspect the compiled resources file (resources.arsc) Ensure your APK contains exactly the things you expect
41. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
42. Battery Consumption Eliminate unneeded wakeups Batch network requests Use GcmNetworkManager API
43. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
44. Fast & Responsive UI Touch feedback everywhere UI always interactive Always target 60 fps Consider launch screens Source : nkdroidsolutions.com
45. Implementing Ripple effect <RelativeLayout android:id="@+id/rlCarDetailsPUC" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="?attr/selectableItemBackground"> <android.support.v7.widget.CardView android:layout_width="match_parent" android:layout_height="wrap_content" app:cardCornerRadius="@dimen/dimen_5_dp" android:foreground="?attr/selectableItemBackground" app:cardElevation="@dimen/common_card_elevation" app:cardUseCompatPadding="true"> Layout - Set background CardView - Set foreground
46. Implementing Ripple effect <TextView . . android:background="?attr/selectableItemBackgroundBorderless" android:clickable="true" /> <ImageView . . . android:background="?attr/selectableItemBackgroundBorderless" android:clickable="true" /> TextView - selectableItemBackgroundBorderless ImageView - Use selectableItemBackgroundBorderless
47. Implementing Ripple effect - Button <?xml version="1.0" encoding="utf-8"?> <ripple xmlns:android="http://schemas.android.com/apk/res/android" android:color="@color/colorPrimaryDark"> <item android:drawable="@color/colorPrimary" /> </ripple> <?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:state_pressed="true" android:drawable="@color/colorPrimaryDark"/> <item android:drawable="@color/colorPrimary"/> </selector> drawable-v21/ drawable/
48. Consider launch screens It’s a user’s first experience of your app Use a placeholder UI Or a branded launch screen
49. UI Best Practices Adhere to Material Design Use Design Support library
50. Localization Support your user’s locale User appropriate fonts (e.g. Noto)
51. Developing for Billions Framework 1.Connectivity 2.Device Capability 3.Data Cost 4.Battery Consumption 5.Content 6.Commerce
52. Monetization Advertisement In-App Purchase Subscription Paid App
53. Local Price Sub-dollar prices available in over 18 countries Helps offer locally affordable products
54. Bonus Tips
55. Introduction Screens Don’t assume your app’s all users are literate Guide your users Show Important features of your app
56. Prepare Wireframe/Mockups Because App Developers are not magicians...
57. Prepare Wireframe/Mockups
58. Don’t wait for your Users to submit Crash Reports At that moment when you users are saying app is being crashed
59. You would not come to know about crashes being faced by users, until they submit voluntarily Then how to get it automatically? Use tools like Crashlytics, Firebase, Crittercism, ACRA Don’t wait for your Users to submit Crash Reports
60. Use Version Control System Have developed scalable app Have proper architecture followed Use patterns => MVP / MVVM Use OkHttp, Retrofit, RxJava, RxAndroid More tips/best practices
61. Building for Billions Playbook g.co/play/billionsplaybook What’s Next ? Building for Billions Framework g.co/dev/billions
62. No Questions!
63. Thank you! Paresh Mayani @pareshmayani