diff --git a/COPYING b/LICENSE
similarity index 100%
rename from COPYING
rename to LICENSE
diff --git a/README.md b/README.md
index dc25af9b..ab59bbd2 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ DAVDROID
 Please see the [DAVdroid Web site](https://davdroid.bitfire.at) for
 detailled information about DAVdroid.
 
-DAVdroid is licensed under the [GPLv3 License](COPYING).
+DAVdroid is licensed under the [GPLv3 License](LICENSE).
 
 News and updates: [@davdroidapp](https://twitter.com/davdroidapp)
 
@@ -17,6 +17,8 @@ Parts of DAVdroid have been outsourced into these libraries:
 * [ical4android](https://gitlab.com/bitfireAT/ical4android) – iCalendar processing and Calendar Provider access
 * [vcard4android](https://gitlab.com/bitfireAT/vcard4android) – VCard processing and Contacts Provider access
 
+[![Flattr this!](https://api.flattr.com/button/flattr-badge-large.png)](https://flattr.com/submit/auto?user_id=bitfire&url=https://davdroid.bitfire.at&title=DAVdroid&category=software)
+
 
 USED THIRD-PARTY LIBRARIES
 ==========================
diff --git a/ical4android b/ical4android
index 7df1b515..46d23fb4 160000
--- a/ical4android
+++ b/ical4android
@@ -1 +1 @@
-Subproject commit 7df1b5156073fda73ac36117189acbaa8a5ce2f0
+Subproject commit 46d23fb4ff276f4efb317069b7c072d5c29ba4d2