JEFIT not only allows you to download Routines from the database but you can also create one. You can do so by going into the website so that it'll be more convenient to setup your own routine.
Please see screenshots below and follow accordingly.
Step 5 : Locate the new routine you created from the routine manager's page:
Step 6: Go to the Routine Main Page
Then add your workout day and click the Edit button to add exercises
Step 7 Add as many exercises you like:
Step 8: Force Sync Everything and sync to the app.
Follow the guide here: https://www.jefit.com/jefit-product-tips-faq/force-synchronization/
On your android app, just go to Workout Plans then find your routine.
On the app: