Instagram's most famous model Jen Selter has definitely developed over the months with images that show how much she's improved her body.

Jen Selter Flaunts Her Booty As She Embraces Her Inner Child

Selter became a big deal when she started posting snapshots of herself at the gym where her muscles became more visible within each picture. The slideshow on this page shows some before and after shots of the model that present a time when the model was less curvy and how much that's changed. What started off as a petite girl turned into a woman with hard abs, thick legs and an iconic behind.

One of Selter's most recent images posted on Monday is an ab shot of her washboard stomach. She wears a black sports bra with tight pants where a glimpse of her cleavage can be seen as well.

Jen Selter Bares Her Backside In Tiny Bikini Bottoms, Check Out The PHOTO

She captioned the image, "Good morning loves @iamfitmiss #MondayMotivation."

Another random shot of Selter shows off her belly as she dons a Batgirl costume for Halloween weekend.

Check out the slideshow to see where Selter was in the past and how she became the fitness expert she is today with more than four million followers on Instagram.