A Product / Service has two components to it: The Item Code and the Item Name.
By default, the app sorts by Item Name. If your products are alphabetized by the code, then they will appear to be out of order in the app.
Here's how to fix it:
1. From your computer, login into the Web Dashboard
2. Click on Settings.
3. Click on Inventory Settings.
4. Click on the drop-down menu under Item Sort Preference.
Change it from Product Name to Item Code and save it.