Yes, DEVELOPING is a Scrabble word!

Letter values in Scrabble US: D 2, E 1, V 4, E 1, L 1, O 1, P 3, I 1, N 1, G 2.

Is it a valid word?

DEVELOPING is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

make something new, such as a product or a mental or artistic creation
work out
gain through experience
come to have or undergo a change of (physical features and attributes)
come into existence; take on form or shape
change the use of and make available or usable
elaborate, as of theories and hypotheses
create by training and teaching
be gradually disclosed or unfolded; become manifest;
grow, progress, unfold, or evolve through a process of evolution, natural growth, differentiation, or a conducive environment
become technologically advanced
cause to grow and differentiate in ways conforming to its natural development
generate gradually
grow emotionally or mature
make visible by means of chemical solutions
superimpose a three-dimensional surface on a plane without stretching, in geometry
move one's pieces into strategically more advantageous positions
move into a strategically more advantageous position
elaborate by the unfolding of a musical idea and by the working out of the rhythmic and harmonic changes in the theme
happen
expand in the form of a series

relating to societies in which capital needed to industrialize is in short supply

Also: spring up, build up, make grow.