diff --git a/.gitignore b/.gitignore
index 7be3f9a..ea198f3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,2 @@
-local.properties
-proguard-project.txt
-bin/*
-gen/*
 *.keystore
+_build
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..66e251f
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,111 @@
+# Configuration
+
+PACKAGE_NAME = juloo.keyboard2
+
+ANDROID_PLATFORM_VERSION = android-29
+JAVA_VERSION = 1.7
+
+SRC_DIR = srcs
+ASSETS_DIR = assets
+RES_DIR = res
+
+EXTRA_JARS =
+
+# /
+
+debug: _build/$(PACKAGE_NAME).debug.apk
+release: _build/$(PACKAGE_NAME).apk
+
+installd: _build/$(PACKAGE_NAME).debug.apk
+	adb install "$<"
+
+.PHONY: release debug installd
+
+$(shell mkdir -p _build)
+
+ifndef ANDROID_HOME
+$(error ANDROID_HOME not set)
+endif
+
+ANDROID_BUILD_TOOLS = $(lastword $(sort $(wildcard $(ANDROID_HOME)/build-tools/*)))
+ANDROID_PLATFORM = $(ANDROID_HOME)/platforms/$(ANDROID_PLATFORM_VERSION)
+
+ifeq ($(shell [ -d "$(ANDROID_PLATFORM)" ] && echo ok),)
+$(error Android platform not found. Want $(ANDROID_PLATFORM_VERSION), \
+	found $(notdir $(wildcard $(ANDROID_HOME)/platforms/*)))
+endif
+
+JAVAC_FLAGS = -source $(JAVA_VERSION) -target $(JAVA_VERSION) -encoding utf8
+
+# Source files
+
+MANIFEST_FILE = AndroidManifest.xml
+JAVA_FILES = $(shell find $(SRC_DIR) -name '*.java')
+RES_FILES = $(shell find $(RES_DIR) -type f)
+ASSETS_FILES = $(shell find $(ASSETS_DIR) -type f 2>/dev/null)
+
+# Align
+
+_build/%.apk: _build/%.signed-apk
+	$(ANDROID_BUILD_TOOLS)/zipalign -fp 4 "$<" "$@"
+
+# Debug signing
+
+DEBUG_KEYSTORE = _build/debug.keystore
+DEBUG_PASSWD = debug0
+
+$(DEBUG_KEYSTORE):
+	echo y | keytool -genkeypair -dname "cn=d, ou=e, o=b, c=ug" \
+		-alias debug -keypass $(DEBUG_PASSWD) -keystore "$@" \
+		-keyalg rsa -storepass $(DEBUG_PASSWD) -validity 10000
+
+_build/%.debug.signed-apk: _build/%.debug.unsigned-apk $(DEBUG_KEYSTORE)
+	jarsigner -keystore $(DEBUG_KEYSTORE) \
+		-storepass $(DEBUG_PASSWD) -keypass $(DEBUG_PASSWD) \
+		-signedjar "$@" "$<" debug
+
+# Debug apk
+
+_build/$(PACKAGE_NAME).debug.unsigned-apk: AAPT_PACKAGE_FLAGS+=--rename-manifest-package $(PACKAGE_NAME).debug
+
+# Release signing
+
+# %-keystore.conf should declare KEYSTORE, KEYNAME and OPTS
+#  it is interpreted as a shell script
+# OPTS can be used to pass -storepass or -keypass options to jarsigner
+_build/%.signed-apk: _build/%.unsigned-apk %-keystore.conf
+	eval `cat $(word 2,$^)` && \
+	jarsigner -keystore "$$KEYSTORE" $$OPTS -signedjar "$@" "$<" "$$KEYNAME"
+
+# Package
+
+_build/%.unsigned-apk: _build/classes.dex $(MANIFEST_FILE) $(ASSETS_FILES)
+	$(ANDROID_BUILD_TOOLS)/aapt package -f -M $(MANIFEST_FILE) -S $(RES_DIR) \
+		-I $(ANDROID_PLATFORM)/android.jar -F "$@" $(AAPT_PACKAGE_FLAGS)
+	[ -z "$(ASSETS_FILES)" ] || $(ANDROID_BUILD_TOOLS)/aapt add "$@" $(ASSETS_FILES)
+	cd $(@D) && $(ANDROID_BUILD_TOOLS)/aapt add $(@F) classes.dex
+
+# R.java
+
+GEN_DIR = _build/gen
+R_FILE = $(GEN_DIR)/$(subst .,/,$(PACKAGE_NAME))/R.java
+
+$(R_FILE): $(RES_FILES) $(MANIFEST_FILE)
+	mkdir -p "$(@D)"
+	$(ANDROID_BUILD_TOOLS)/aapt package -f -m -S $(RES_DIR) -J $(GEN_DIR) \
+		-M $(MANIFEST_FILE) -I $(ANDROID_PLATFORM)/android.jar
+
+# Compile java classes and build classes.dex
+
+OBJ_DIR = _build/class
+# A$B.class files are ignored
+# CLASS_FILES = $(JAVA_FILES:$(SRC_DIR)/%.java=$(OBJ_DIR)/%.class) \
+# 	$(R_FILE:$(GEN_DIR)/%.java=$(OBJ_DIR)/%.class)
+
+_build/classes.dex: $(JAVA_FILES) $(R_FILE)
+	mkdir -p $(OBJ_DIR)
+	javac -d $(OBJ_DIR) $(JAVAC_FLAGS) \
+		-classpath $(ANDROID_PLATFORM)/android.jar:$(EXTRA_JARS) \
+		-sourcepath $(SRC_DIR):$(GEN_DIR) \
+		$^
+	$(ANDROID_BUILD_TOOLS)/dx --dex --output="$@" $(OBJ_DIR) $(subst :, ,$(EXTRA_JARS))
diff --git a/ant.properties b/ant.properties
deleted file mode 100644
index 190cdd5..0000000
--- a/ant.properties
+++ /dev/null
@@ -1,23 +0,0 @@
-# This file is used to override default values used by the Ant build system.
-#
-# This file must be checked into Version Control Systems, as it is
-# integral to the build system of your project.
-
-# This file is only used by the Ant script.
-
-# You can use this to override default values such as
-#  'source.dir' for the location of your java source folder and
-#  'out.dir' for the location of your output folder.
-source.dir=srcs
-
-# You can also use it define how the release builds are signed by declaring
-# the following properties:
-#  'key.store' for the location of your keystore and
-#  'key.alias' for the name of the key to use.
-# The password will be asked during the build when you use the 'release' target.
-
-key.store=release-keys.keystore
-key.alias=releasekey
-
-java.source=1.7
-java.target=1.7
diff --git a/build.xml b/build.xml
deleted file mode 100644
index 8e58243..0000000
--- a/build.xml
+++ /dev/null
@@ -1,92 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project name="Keyboard2" default="help">
-
-    <!-- The local.properties file is created and updated by the 'android' tool.
-         It contains the path to the SDK. It should *NOT* be checked into
-         Version Control Systems. -->
-    <property file="local.properties" />
-
-    <!-- The ant.properties file can be created by you. It is only edited by the
-         'android' tool to add properties to it.
-         This is the place to change some Ant specific build properties.
-         Here are some properties you may want to change/update:
-
-         source.dir
-             The name of the source directory. Default is 'src'.
-         out.dir
-             The name of the output directory. Default is 'bin'.
-
-         For other overridable properties, look at the beginning of the rules
-         files in the SDK, at tools/ant/build.xml
-
-         Properties related to the SDK location or the project target should
-         be updated using the 'android' tool with the 'update' action.
-
-         This file is an integral part of the build system for your
-         application and should be checked into Version Control Systems.
-
-         -->
-    <property file="ant.properties" />
-
-    <!-- if sdk.dir was not set from one of the property file, then
-         get it from the ANDROID_HOME env var.
-         This must be done before we load project.properties since
-         the proguard config can use sdk.dir -->
-    <property environment="env" />
-    <condition property="sdk.dir" value="${env.ANDROID_HOME}">
-        <isset property="env.ANDROID_HOME" />
-    </condition>
-
-    <!-- The project.properties file is created and updated by the 'android'
-         tool, as well as ADT.
-
-         This contains project specific properties such as project target, and library
-         dependencies. Lower level build properties are stored in ant.properties
-         (or in .classpath for Eclipse projects).
-
-         This file is an integral part of the build system for your
-         application and should be checked into Version Control Systems. -->
-    <loadproperties srcFile="project.properties" />
-
-    <!-- quick check on sdk.dir -->
-    <fail
-            message="sdk.dir is missing. Make sure to generate local.properties using 'android update project' or to inject it through the ANDROID_HOME environment variable."
-            unless="sdk.dir"
-    />
-
-    <!--
-        Import per project custom build rules if present at the root of the project.
-        This is the place to put custom intermediary targets such as:
-            -pre-build
-            -pre-compile
-            -post-compile (This is typically used for code obfuscation.
-                           Compiled code location: ${out.classes.absolute.dir}
-                           If this is not done in place, override ${out.dex.input.absolute.dir})
-            -post-package
-            -post-build
-            -pre-clean
-    -->
-    <import file="custom_rules.xml" optional="true" />
-
-    <!-- Import the actual build file.
-
-         To customize existing targets, there are two options:
-         - Customize only one target:
-             - copy/paste the target into this file, *before* the
-               <import> task.
-             - customize it to your needs.
-         - Customize the whole content of build.xml
-             - copy/paste the content of the rules files (minus the top node)
-               into this file, replacing the <import> task.
-             - customize to your needs.
-
-         ***********************
-         ****** IMPORTANT ******
-         ***********************
-         In all cases you must update the value of version-tag below to read 'custom' instead of an integer,
-         in order to avoid having your file be overridden by tools such as "android update project"
-    -->
-    <!-- version-tag: 1 -->
-    <import file="${sdk.dir}/tools/ant/build.xml" />
-
-</project>
diff --git a/project.properties b/project.properties
deleted file mode 100644
index 8218193..0000000
--- a/project.properties
+++ /dev/null
@@ -1,14 +0,0 @@
-# This file is automatically generated by Android Tools.
-# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
-#
-# This file must be checked in Version Control Systems.
-#
-# To customize properties used by the Ant build system edit
-# "ant.properties", and override values to adapt the script to your
-# project structure.
-#
-# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
-#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
-
-# Project target.
-target=android-29
diff --git a/shell.nix b/shell.nix
index 3f6d853..fc29b4c 100644
--- a/shell.nix
+++ b/shell.nix
@@ -14,9 +14,7 @@ in
 
 pkgs.mkShell {
   buildInputs = with pkgs; [
-    ant openjdk8 android.androidsdk
+    findutils openjdk8 android.androidsdk
   ];
-  shellHook = ''
-    export ANDROID_HOME=${android.androidsdk}/libexec/android-sdk
-  '';
+  ANDROID_HOME = "${android.androidsdk}/libexec/android-sdk";
 }