Thank you ! Here are two simple options for sending any additional contribution of your choosing :

#1 : Paypal

Once you're logged into your PayPal Account, choose "Send a payment". Then under "recipient", simply indicate my  PayPal email, which is
[email protected]
Please specify "donation", as no fees will be applied then

#2 Bank Transfer

Send the amount of your choosing to my account at GLS Gemeinschaftsbank,
Christstraße 9, 44789 Bochum, Germany
IBAN: DE50 4306 0967 2057 0019 00
 BIC: GENODEM1GLS