Engineers Without Borders Usa Inc
This organization organizes volunteer engineering and design work aimed at "empowering communities to meet their basic needs". Consider volunteering in addition to donating!
D Rev Design For The Other Ninety Percent
d-Rev is focused on building medical devices for people living on less that $1.25 per day. Not by using cheap materials, but by employing elegant design principals.
Evidence Action Inc
This fund is remarkable for how they build their programs and TEST them for effectiveness. It is the way philanthropy should be measured. https://www.vox.com/2018/11/29/18114585/poverty-charity-randomized-controlled-trial-evidence-action