Naranja agria (pronounced as one word) is a staple of Nicaraguan kitchen gardens. It is used to acidify foods where one could also use vinegar. The trees eventually get large, so I would leave a spot 15 feet or more in diameter for its ultimate size and fill in the area with other plants for the meantime.
This can be planted fairly close to the house as it does not attract flies and wasps like mango trees. The fruits are often used green, but can be allowed to ripen to yellow. The leaves are also used in tea as a folk remedy for colds and stress.