Behind our fish pond and fountain is a wild-ish plum tree. Its fruit is small and round, deep-red skinned, and red-fleshed. It is not an eating plum as such, but when slightly sweetened makes wonderful jam, chutney, and sauce.
A friend from Australia (who presented an Aussie TV gardening programme) once called it a 'bird plum'; I wouldn't know what to call it, I just think of it as being 'semi-wild'. Whatever its variety, it produces huge amounts of fruit annually, and is an 'essential' in any garden where one has the space.
Being a 'Prunus' it is always the first tree in the garden to flower, and for that alone its place is merited.