Budongo Forest is an excellent spot to track chimpanzees while visiting Murchison Falls Park. The success rate in seeing Chimpanzees is quite high here and only outdone by Kibale Forest.
There are morning and afternoon chimpanzee tracking times and for those visiting Murchison Falls National Park this can be done on the way to or from Murchison Falls National Park adding another activity to your safari there.
The ideal plan would be to stay overnight and also does a forest walk while at Budongo Forest. Do not forget that you can add on Ziwa Rhino Sanctuary where you track Rhinos on foot on your return trip to Kampala.