diff --git a/build-logic/application/build.gradle.kts b/build-logic/application/build.gradle.kts
new file mode 100644
index 000000000..523255e6b
--- /dev/null
+++ b/build-logic/application/build.gradle.kts
@@ -0,0 +1,16 @@
+plugins {
+    `kotlin-dsl`
+}
+
+dependencies {
+    compileOnly(core.gradle.build.tools)
+}
+
+gradlePlugin {
+    plugins {
+        register("infomaniakApplication") {
+            id = "com.infomaniak.core.application"
+            implementationClass = "com.infomaniak.core.application.InfomaniakApplicationPlugin"
+        }
+    }
+}
diff --git a/build-logic/application/src/main/kotlin/com/infomaniak/core/application/InfomaniakApplicationPlugin.kt b/build-logic/application/src/main/kotlin/com/infomaniak/core/application/InfomaniakApplicationPlugin.kt
new file mode 100644
index 000000000..2bd712fdc
--- /dev/null
+++ b/build-logic/application/src/main/kotlin/com/infomaniak/core/application/InfomaniakApplicationPlugin.kt
@@ -0,0 +1,54 @@
+/*
+ * Infomaniak Core - Android
+ * Copyright (C) 2025 Infomaniak Network SA
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.infomaniak.core.application
+
+import com.android.build.api.dsl.CommonExtension
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.configure
+import java.io.File
+
+/**
+ * Configures the shared debug signing certificate for Android application modules.
+ */
+class InfomaniakApplicationPlugin : Plugin<Project> {
+
+    override fun apply(target: Project) {
+        val keystoreFile = listOf(
+            target.rootProject.file("debug.keystore"),
+            target.rootProject.file("Core/config/debug.keystore"),
+            target.rootProject.file("config/debug.keystore"),
+        ).firstOrNull(File::exists)
+
+        requireNotNull(keystoreFile) {
+            "Shared debug keystore not found. Expected it under <rootProject>/debug.keystore or Core/config/debug.keystore."
+        }
+
+        target.rootProject.allprojects {
+            plugins.withId("com.android.application") {
+                extensions.configure<CommonExtension<*, *, *, *, *, *>> ("android") {
+                    signingConfigs {
+                        getByName("debug") {
+                            storeFile = keystoreFile
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/build-logic/settings.gradle.kts b/build-logic/settings.gradle.kts
index 43e6182f6..6244556b7 100644
--- a/build-logic/settings.gradle.kts
+++ b/build-logic/settings.gradle.kts
@@ -15,4 +15,5 @@ rootProject.name = "build-logic"
 include(
     ":composite",
     ":composeLint",
+    ":application",
 )
diff --git a/config/debug.keystore b/config/debug.keystore
new file mode 100644
index 000000000..4b2ff4f49
Binary files /dev/null and b/config/debug.keystore differ
diff --git a/gradle/core.versions.toml b/gradle/core.versions.toml
index 648761eb0..1d124c557 100644
--- a/gradle/core.versions.toml
+++ b/gradle/core.versions.toml
@@ -243,6 +243,7 @@ android-library = { id = "com.android.library", version.ref = "agp" }
 android-kmp-library = { id = "com.android.kotlin.multiplatform.library", version.ref = "agp" }
 compose-compiler = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
 compose-lint = { id = "com.infomaniak.core.compose.lint" }
+infomaniak-application = { id = "com.infomaniak.core.application" }
 dagger-hilt = { id = "com.google.dagger.hilt.android", version.ref = "hiltAndroid" }
 google-services = { id = "com.google.gms.google-services", version.ref = "googleServices" }
 kapt = { id = "org.jetbrains.kotlin.kapt", version.ref = "kotlin" }