diff --git a/app/build.gradle b/app/build.gradle
index dea0b1e898..b74031e69a 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -25,6 +25,9 @@ android {
 
         multiDexEnabled true
 
+        /**
+         * Field changes behaviour of Course purchases for different stores
+         */
         buildConfigField "boolean", "IS_GOOGLE_PLAY", "true"
     }
 
diff --git a/app/src/main/java/org/stepic/droid/configuration/RemoteConfig.kt b/app/src/main/java/org/stepic/droid/configuration/RemoteConfig.kt
index 55431f2730..07f7fced92 100644
--- a/app/src/main/java/org/stepic/droid/configuration/RemoteConfig.kt
+++ b/app/src/main/java/org/stepic/droid/configuration/RemoteConfig.kt
@@ -1,5 +1,7 @@
 package org.stepic.droid.configuration
 
+import org.stepic.droid.BuildConfig
+
 object RemoteConfig {
     const val PREFIX = "remote_config_"
 
@@ -12,7 +14,12 @@ object RemoteConfig {
     const val IS_NEW_HOME_SCREEN_ENABLED = "is_new_home_screen_enabled"
     const val PERSONALIZED_ONBOARDING_COURSE_LISTS = "personalized_onboarding_course_lists"
     const val IS_COURSE_REVENUE_AVAILABLE_ANDROID = "is_course_revenue_available_android"
-    const val PURCHASE_FLOW_ANDROID = "purchase_flow_android_1_218_and_later"
+    val PURCHASE_FLOW_ANDROID =
+        if (BuildConfig.IS_GOOGLE_PLAY) {
+            "purchase_flow_android_1_218_and_later"
+        } else {
+            "purchase_flow_android"
+        }
     const val PURCHASE_FLOW_ANDROID_TEST = "purchase_flow_android_test"
     const val PURCHASE_FLOW_DISCLAIMER_EN = "purchase_flow_android_disclaimer_en"
     const val PURCHASE_FLOW_DISCLAIMER_RU = "purchase_flow_android_disclaimer_ru"
diff --git a/app/src/releaseOldKeys/java/org/stepic/droid/configuration/EndpointResolverImpl.kt b/app/src/releaseOldKeys/java/org/stepic/droid/configuration/EndpointResolverImpl.kt
new file mode 100644
index 0000000000..6daef3f749
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepic/droid/configuration/EndpointResolverImpl.kt
@@ -0,0 +1,19 @@
+package org.stepic.droid.configuration
+
+import org.stepik.android.remote.auth.model.TokenType
+import javax.inject.Inject
+
+class EndpointResolverImpl
+@Inject
+constructor(
+    private val config: Config
+) : EndpointResolver {
+    override fun getOAuthClientId(type: TokenType): String =
+        config.getOAuthClientId(type)
+
+    override fun getBaseUrl(): String =
+        config.baseUrl
+
+    override fun getOAuthClientSecret(type: TokenType): String =
+        config.getOAuthClientSecret(type)
+}
\ No newline at end of file
diff --git a/app/src/releaseOldKeys/java/org/stepic/droid/util/DebugToolsHelper.kt b/app/src/releaseOldKeys/java/org/stepic/droid/util/DebugToolsHelper.kt
new file mode 100644
index 0000000000..d93f754ea0
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepic/droid/util/DebugToolsHelper.kt
@@ -0,0 +1,13 @@
+package org.stepic.droid.util
+
+import android.app.Application
+import okhttp3.Interceptor
+
+object DebugToolsHelper {
+    fun initDebugTools(app: Application) {
+        // no op
+    }
+
+    fun getDebugInterceptors(): List<Interceptor> =
+        emptyList()
+}
diff --git a/app/src/releaseOldKeys/java/org/stepik/android/view/debug/ui/fragment/DebugMenu.kt b/app/src/releaseOldKeys/java/org/stepik/android/view/debug/ui/fragment/DebugMenu.kt
new file mode 100644
index 0000000000..531c3050e2
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepik/android/view/debug/ui/fragment/DebugMenu.kt
@@ -0,0 +1,10 @@
+package org.stepik.android.view.debug.ui.fragment
+
+import androidx.fragment.app.Fragment
+
+interface DebugMenu {
+    companion object {
+        const val TAG = "DebugFragment"
+        fun newInstance(): Fragment = Fragment()
+    }
+}
\ No newline at end of file
diff --git a/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/DebugComponent.kt b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/DebugComponent.kt
new file mode 100644
index 0000000000..9f5c09d58e
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/DebugComponent.kt
@@ -0,0 +1,11 @@
+package org.stepik.android.view.injection.debug
+
+import dagger.Subcomponent
+
+@Subcomponent
+interface DebugComponent {
+    @Subcomponent.Builder
+    interface Builder {
+        fun build(): DebugComponent
+    }
+}
\ No newline at end of file
diff --git a/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/InAppPurchasesComponent.kt b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/InAppPurchasesComponent.kt
new file mode 100644
index 0000000000..4b83a5e5bd
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/InAppPurchasesComponent.kt
@@ -0,0 +1,11 @@
+package org.stepik.android.view.injection.debug
+
+import dagger.Subcomponent
+
+@Subcomponent
+interface InAppPurchasesComponent {
+    @Subcomponent.Builder
+    interface Builder {
+        fun build(): InAppPurchasesComponent
+    }
+}
\ No newline at end of file
diff --git a/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/SplitTestsComponent.kt b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/SplitTestsComponent.kt
new file mode 100644
index 0000000000..eacd9bfb59
--- /dev/null
+++ b/app/src/releaseOldKeys/java/org/stepik/android/view/injection/debug/SplitTestsComponent.kt
@@ -0,0 +1,11 @@
+package org.stepik.android.view.injection.debug
+
+import dagger.Subcomponent
+
+@Subcomponent
+interface SplitTestsComponent {
+    @Subcomponent.Builder
+    interface Builder {
+        fun build(): SplitTestsComponent
+    }
+}
\ No newline at end of file