I'm renting out my spacious 22sqm bright guest room as part of a 80sqm clean, modern and newly renovated apartment in Friedrichshain. Close to public transportation. Bars, restaurants, supermarkets are around the corner. We share bathroom (you'll have a private acess) and kitchen. If you need a bicycle, I do have a guest bike.
Many friends and family are visiting Berlin, therefore I cannot rent out my guest room for longer periods of time. Ideally 2-3 days to one week.