I am new to Magento and I want to implement an idea for a store that would include on-stop delivery, meaning that the store owner would schedule when and to where is he delivering the products. Customers would then just check "Yes, I will be there to get my order".
Is there an extension for such 'shipping' method? If not can you point me to where I would have to start to make my own?
I am not sure about an extension that can cover two functions as you want, but to schedule time of receiving orders for customers, you should try Order Delivery Date Extension.
This extension allows customers to select the most convenient time and date to get their orders.
Besides, store owners also can set up times and dates or days off to help them have enough time interval to process orders such as processing time, cut off time, day off/exclude days and so on. Moreover, delivery date information is embed into confirmation emails to customers.
Therefore, it's very easy for both customers and store owners to use and make shipping process faster than ever before.