Is there a way to take low resolution pictures on Android? I have a Galaxy S5, and with the native camera app, the smallest possible picture size is a 2.4MB image at 2028x1152 pixels.

However, for the purposes of capturing images for flashcards I use in Ankidroid, that size is too large. The storage volume adds up quickly and the files are slow to move around the network.

What I really want is to take pictures in the realm of 640x480 pixels or so. I don't need high quality, I need small, quick, and disposable.

Are there any camera apps, or any other methods, where I can take low resolution images? My search of Google Play indicates almost all camera apps aspire to take the biggest, sharpest, highest resolution pictures possible.
Open Camera has plenty of options for specifying the resolution. 

Look on the settings menu, then Photo settings. You can set it to 640x480 or even 352x288. You can also set the image quality, ie the level of JPEG compression. If you decrease the quality, it will give you smaller file sizes.