diff --git a/README.md b/README.md
index 00d5e61..b7ce715 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,37 @@
-# thbrd-signature
\ No newline at end of file
+# Signature sync for Gmail, a Thunderbird add-on
+
+<p align="center">
+  <img src="signature-extension/_img/icons8-signature-64.png" />
+</p>
+
+This extension allows you to easily synchronize signature of selected accounts
+in Thunderbird with your Gmail accounts. **Syncronization works in one way**,
+your local signatures are overridden by Gmail ones.
+
+In order to sync a signature, go to the settings page, enable an account and
+connect it with Gmail. Signatures are downloaded on every startup or when you
+click in settings.
+
+> **Beta!** This is still a beta version. It can work unstable.
+
+## Run from source
+
+TODO
+## Privacy & usage terms
+
+The extension is working just locally on your computer. It doesn't send any data
+outside, except of needed requests to Google API. Use it to update your local
+signatures from Gmail.
+
+## External sources
+
+This add-on uses some external resources:
+
+- Files from external libraries, which full list you can find in
+  the license file [\_lib directory](signature-extension/_lib/LICENSE.md)
+- Signature icon from [Icon8](https://icons8.com), you can find more in
+  the license file in [\_img directory](signature-extension/_img/LICENSE.md)
+
+----
+
+This extension is **not** made by Google or Thunderbird team. It's fully unofficial.
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diff --git a/signature-extension/_img/LICENSE b/signature-extension/_img/LICENSE
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+++ b/signature-extension/_img/LICENSE
@@ -0,0 +1,5 @@
+Files with name containig "icons8" come from https://icons8.com on free use licence.
+See https://icons8.com/license for details
+
+List of the licensed icons:
+* https://icons8.com/icons/set/signature Signature icon
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diff --git a/signature-extension/_img/icons8-signature-64.png b/signature-extension/_img/icons8-signature-64.png
new file mode 100644
index 0000000..1b1ee07
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diff --git a/signature-extension/manifest.json b/signature-extension/manifest.json
index f42d08f..ed43c7b 100644
--- a/signature-extension/manifest.json
+++ b/signature-extension/manifest.json
@@ -4,6 +4,9 @@
   "version": "1.0.0",
   "author": "Kamil Mankowski",
   "description": "Sync your signatures with Gmail accounts",
+  "icons": {
+    "64": "_img/icons8-signature-64.png"
+  },
   "applications": {
     "gecko": {
       "id": "signature-sync@thunderbird.extensions.kam193",