Apart from the full-customization smartphone concepts like Phoneblok and Project Ara which are yet to materialize, so far, you only get to customize the outer shell of the device and change the looks.
However, that is enough for the most smartphone users to make their devices look better and make it suit the owner's get-up. One phone which offers these kind of outer shell customization comes from Motorola.
2013:wood::2014:leather— @evleaks (@evleaks) April 6, 2014
Motorola's Moto Maker customization options have already offered a wood finishing on the Moto X device. The phone with the wooden finish is not a normal view for ordinary people and very rarely you get to see these phones. But Motorola has not only gave it a woody look, moreover, the company has also made an array of color choices with the College Collection. Thus you already have a number of choices to customize your Moto X devices externally.
Now one of the most efficient tech-bound leakster @evleaks has come up with a tweet which just reads, "2013:wood::2014:leather," and it is pretty evident that the prolific Twitter user is actually talking about the Moto X covers. It surely makes a great deal of difference to the users as the leather back panel has become one of the catchy tend in the smartphone market, which has been mostly used by Samsung in the form of faux leather finish.
Moreover, to talk about Motorola, if you can remember the company had also offered a bamboo backs as an option in Moto Maker in 2013, though, it seems plausible that the message could be hinting that a leather option will be available in Moto Maker in 2014.