Appropriate Technology

See Wikipedia's entry for Appropriate Technology 
Organizations:

• Practical Action is one probably the oldest appropriate technology organization. 
• Compatible Technology: Food processors, water purification.

Wood cooking stove technologies: Journey to Forever, ClimateTechWiki...
Biochar and cooking stoves.
Genetic engineering: golden rice, BioCassava, Aresa Biodetection
Charcoal briquette production from sugarcane waste (bagasse)
Lighting: LEDs, water bottle sky lights. 
Electricity generation
Bicycles and transport: Bamboo bike, Worldbike
Education: Project H
Sanitation and Sewage:  Daily Dump: Indian composting service and equipment.
Finance:
Water:

• purification: SODIS
• transport: hippo water roller
• collection (rainwater, dew collector, fog, solar still)
• pumping
• irrigation

Health

• Plumpynut
• LED Jaundice lamps
• syringe storage
• Vision: Adaptive eyewear
• Wheelchairs
• Prosthetics
• Vaccine tech

Security

• Mine sweeping: spider boot

Housing: Disaster resistant architecture
Refugee housing

Appropriate Technology is great and makes a huge impact on people's lives, but it isn't a panacea that can measurably grow median incomes.  That requires numerous technologies and systemic changes.  But each appropriate technology helps improve people's lives.  Some even save lives.  That helps nudge towards a tipping point of long-run systemic change.  Even Gutenberg's invention of the printing press did not have a direct measurable impact on GDP, but it helped propel Europe and then the globe towards that tipping point of economic development.