Leopard geckos are considered adults at 1 year old, but they often continue to grow until about 2 years old. They do majority of their growing during their first year. Their growth rate will slow down after 1 year old but they often do continue to grow, but usually more in weight than length.
Agreed....
For instance. Had a female reach 57g at 1 yr old. At a little over 2 years old, she's now 74g. Hasn't grown in length much (maybe 1/4" at the most) but certainly outgrew the "lanky" stage.
I have a large male that hatched mid summer of last year. So almost a year and a half old. He has been sitting at 121 grams consistently now for a few months.