Isn't that a built in stock feature? Just go to your photos app, select an album but make sure you're not looking at one specific picture. At the bottom of the screen is the arrow button which allows you to send the image. Press that arrow, then select a bunch of photos to text. As you select each pic, a little red checkmark appears on each pic. If bitesms is your texting app, all the pics you selected will be sent via bite when you select send via message.