[Desire 820 Q&A, Help & Troubleshooting] rkabishi:
here is the Link for Gapps: http://www.nduoa.com/apk/detail/814257. Go for the 3.0 version.If you google (GMS安装器 apk )on the first link you click on "translate this page " you will have a translated version of that link and download version 3 of that GMS apps. Then i follow this procedure from one member of this xdadevelloper:

Ok, so after dealing with this phone for a while I found many solutions for the common problems of having an imported phone from china.

I found solutions for: Google Apps, Root, CallerID mismatch (Contacts not recognized when receiving calls due to chinese format of their CallerID)

- How to install Google Apps

1. Do a Factory Reset of your phone in the recovery screen (volume down+power button)

2. Download the GMS安装器 apk in your computer from google or any other source, make sure it's the apk with the android robot with the google apps logo in it. (app is no longer distributed in the included App Market)

3. Tranfer the downloaded file to a SD card (32gb maximum size or else it wont be recognized)

4. Insert the SD card in your phone

5. Using the "File Transfer" app in your phone copy the GMS app to the phone's "Download" folder.

6. Enable "Unknown Sources" in Settings/Security/Device Administration

7. Install the App, DON'T RUN IT. (Installation failed for me at first, a factory reset solved this)

8. Unmount the SD Card

9. Using the "File Transfer" app, install the GMS apk

10. Follow the instructions the GMS app is giving you, remember to remove the SD card before installation

11. The app will download something like 200mb, after that it will ask you to enter a code in your phone's dialer, enter it, it will automatically will reboot.

12. If you are lucky, the phone will have all Google Apps installed.

- Root

Once you have Google apps installed, it's easier for some root exploits to work.

1. Use Kingo Root for windows, it will try many methods of Rooting your device, the one that worked used an installation of various apps. Kingo root needed "USB Debugging" activated in Settings/Developer Options. If you don't have the Developer options menu enabled, please google it.

Once you have Root access it's easier to remove the Chinese apps that came with the phone.

- How to fix the CallerID not recognizing contacts problem

1. Download and Install "ES File Explorer" using the Google Play Store app.

2. Allow Root access when prompted to.

3. Head over to the "Tools" menu using the button in the upper left corner of the "ES File Explorer" app.

4. Enable "Root Explorer"

5. Click on "Root Explorer"

6. Click on "Mount R/W

7. Set "/system" to the RW value.

8. Press OK

9. Navigate to: Local, then /Device/system

10. Look for file named: "build.prop" and open it

11. Open it using ES Note Editor

12. Edit the file (using the 3 dots menu on the upper right corner)

13. Find the entry named: ro.phone.min_match=11 and change the number to 7.

14. Entry has to be named ro.phone.min_match=7

15. Press the return button, it will ask you to save changes, save them.

16. Just in case, remove the RW access mentioned in step 7.

17. Go to Settings/apps/all/ contacts and force stop, clear data

18. Do the same with the Contact Storage App.

19. Reboot Phone, cross your fingers and problem is solved.

I hope this helps a lot of people.

BTW: My phone is an HTC 820us, China Mobile.

i did this after flashing the phone with rom from needrom.

At the end of the process i had google play and i install all other google apps(gmail,ect....)

hope this will help