I really love the Wemos D1 mini platform! I bought one of those little WiFi enabled boards a few weeks ago and I've been playing around with it for quote some time now. One of the most interesting things was controlling it using the Blynk App. There's a good Instructable on that as well. A must read as well when you're not familiar yet with setting up your Arduino IDE for the Wemos D1 board (see the steps in Step 2)
The Wemos D1 mini family has 9 shields (10 if you count the prototype shield in as well). If you're not familiar with the concept of shields yet, those are tiny little add-on/plug-in boards with specific "add-on" functionality. See the full lineup here. One of those boards adds a 0.66" OLED display, but the cheapest listing I could find was a little over €5,- so I searched for a similar generic OLED module. I stumbled upon a slightly bigger (0.96 inch) and cheaper (€3,54) module with the same chipset: SSD1306. This was the ebay listing. A quick Google search taught me that this is a widely supported chipset for an OLED display. There's even an Adafruit library for the Arduino platform. So I figured it would be a breeze to use this on my Wemos D1 mini. Well... It would have been if someone would have written this Instructable before I did...
The first thing that was a little off - and I didn't notice when I ordered it - was that the module that I ordered has far more pins in use than the shield, which only uses 2 (and 2 for power). The shield only has an I2C interface while the module I bought supports both I2C and SPI.