Thank you for your question and your interest in the Delivery.com App Challenge. We wish we did not have to exclude countries from global competitions. Unfortunately, it is legally complicated to run prize-based competitions in some countries due to their local contest regulations. By no means is this a statement as to whether international developers are valued or not. They are! It's just a matter of complying with both US and local laws.
You are still certainly welcome to create an app using the Delivery.com API and post it to your portfolio, but unfortunately you will not be eligible to win a prize in this competition.
Thanks for your question and your interest in the Delivery.com App Challenge. Per the official rules:
"The Challenge is not open to, and the following are not eligible to enter and participate to the Challenge... any individuals who are residents of, or organizations domiciled in, a country, state, province or territory where any local law, rule or regulation, or any law, rule or regulation of the United States, prohibits or restricts entering, participating or receiving a prize in the Challenge (including, but not limited to, Brazil, Quebec, Italy, Cuba, Sudan, Iran, North Korea, Syria, and any other country designated by the United States Treasury's Office of Foreign Assets Control);"
Based on that rule, participants from Germany are eligible to participate as long as they meet the other eligibility criteria listed in the rules. I would encourage you to read through Section 3 of the official rules (http://deliveryapps.challengepost.com/rules) to confirm your eligibility.