If you want to make a donation you can use the following methods:

1. Via the German platform Paydirekt to android-development@gmx.de
2. Send Bitcoins to the address: bc1qf9hqymh0qeunvkj95jrl9vtagjsmxuc7c7dle5
3. Paypal
   You can use the link, but Paypal keeps a relatively high comission. So it would be highly appreciated if you could instead make a transfer manually using the "friends" option. Send it to android-development@gmx.de
4. Liberapay