"This productivity app does one thing and it does it very well." - AppAdvice
Templates Saver (for Pages, Keynote, Numbers) allows you to save your Pages, Keynote and Numbers files to the template choosers in Pages, Keynote and Numbers.
HOW IT WORKS
Step 1:
Import the file you wish to save to the template chooser.
Step 2:
Once imported, Templates Saver (for Pages, Keynote, Numbers) automatically converts the file into a template.
Step 3:
Save the file to the template chooser.
IMPORTANT
This app only works with files imported from Pages, Keynote and Numbers. Pages, Keynote and Numbers are apps from Apple, which have to be purchased separately.