plum, maybe; the fruit will tell you in due course
apple; impossible to tell which one (species/cultivar) at this stage
pear; impossible to tell which one (species/cultivar) at this stage
plum/damson, maybe; the fruit will tell you in due course
Note: with Prunus (plum/damson/cherry/gage), beware pruning other than in July.
I know that may seem contrary to normal pruning practice for deciduous trees, but all Prunus are susceptible to silverleaf (a fungal disease). Pruning at 'normal' times of the year gives the disease the best chance to get in. Pruning in July, still poses a risk, by virtue of the open tissues, but the tree is best able to heal the wounds quickest at that time of year.
Longer-term, when pruning Prunus, try to develop/manage the branch structure early, so you cut only small branches. That's for the same reason really - to reduce the amount of time cuts are open and at risk of infection (not only from silver leaf but bacteria canker and other diseases).
With all this, you're only mitigating the risk, not eliminating it. But it is worth doing, IMO.