Re: Looking for a plant ID (leaves have violet underside when hit by light)
These look like a species of "day flower" - a Commelina species and a striped "wandering jew" - Tradescantia species. They are very hardy, flexible plants (in our out of the viv really). I find them too rambunctious for long-term vivarium growth and their leaves look nicer when grown as a houseplant too. Being hardy and fast-growing, however, many people find them useful in their tanks.