Spy Android App Fiddler

1) GET APK
2) decompile with APKTOOL
3) Create /res/xml/network_security_config.xml

<network-security-config>
<base-config>
<trust-anchors>
<certificates src="system"/>
<certificates src="user"/>
</trust-anchors>
</base-config>
</network-security-config>

4) Declare network_security_config.xml to AndroidManifest.xml
<application android:networkSecurityConfig="@xml/network_security_config">

5) Compile with APKTOOl
6) Sign with uber-apk-signer-1.0.0.jar
7) Install APK to mobile
8) Install DRONY and

On your android device, go to Settings -> Wi-Fi -> Long press the wifi ssid (in my case myHotspot) -> In the popup, press Modify Network Config -> Check Show advanced options -> Scroll down and set Proxy settings to Manual -> Set Proxy hostname to localhost -> Set Proxy port to 8020 -> And click Save.
Go to Drony app on your device -> Settings tab -> Uncheck Proxy is visible from outside -> Proxy port 8020 -> Scroll down and in the Networks section, Press Wi-fi -> In the Network list, scroll down and select your wifi hotspot that's running (you should see localhost:8020 below it's ssid) -> Set Proxy type to Manual -> Set Hostname to the IP address or domain name of your Fiddler -> Port 8888 -> Set Domain or Realm to home  -> Go to the Home tab in Drony and Press ON at the bottom. That's it.

9) Enjoy Fiddler and android together
https://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/ConfigureForAndroid