The app comes bundled with 5 sample recipes. If you start the app the first time you are asked if you want to import the bundled ones.
The easiest way to create a backup of your recipes is to save them on iCloud or Google drive. Select a recipe and tap on the share button. Select the 'Save on iCloud' button and select a directory where you want to store it. If you delete the recipe by mistake, you can add it back by tapping on the '+' button and select 'Import from iCloud Drive'. Make sure that you have enabled iCloud drive in the settings view accessible trough the side menu.
Yes. Let's Cook! allows you to modify the contents e.g. add new photos to a recipe which was shared with you to give it a personal touch. You can add notes to a recipe to annotate it adding missing hints, steps or images if you find it confusing. Of course others can change recipes you shared with them as well. You find the authors name in the recipe. Be careful to add your own images or add the source of the image not to infringe copyright laws.
Stay tuned. We are translating the webseite into german now and will release it as soon as possible.