The SSD1306 is a popular display controller for monochrome displays. They are offered in various sizes and resolutions. The SSD1306 supports both I²C and SPI. I only boards wired up for I²C. One thing to be aware of, the pinout may differ. As the top two 0.96″ models show, the VCC and GND are swapped. Not paying attention to such details can ruin your day.