The SSD1309 is compatible with the SSD1306.
This 2"42 OLED needs to be modified for I2C : remove a resistor, add three straps, connect the DC pin to zero for @0x3C or 3v3 for @0x3D...
The RES (reset) pin is more tricky and i had to experiment quite a lot before having something on the screen. 
At the moment i use a little RC circuit so that the OLED display resets automatically on power up... but i think it needs some more experimentation to say if it is reliable enough. (without this RC the OLED does not work)
VDD
|
| | 10k
|
+----------+-------->Res pin
| |
----- 68nF | | 100k
----- |
| |
GND GND
Here are a 2.42" a 0.96" and a 1.3" displays.