What software is best for creating Mobile Checklists

Magnetman12 - PowerApps is the best option if you're looking for a solution that doesn't cost anything (as its included in the Office365 plan). Agree, not always as simple as it sounds but with a little trial & error you should be able to get there. Try searching on YouTube, there's always someone out there with the same problem and a video to fix it (I searched & found https://www.youtube.com/watch?v=Kl6LqNfhGRY) or, if you have some funds, look for someone that makes PowerApps for a living. One guy (https://www.youtube.com/channel/UC7_OGRP8BYvtGB8eZdPG6Ng) that does a lot of tutorials also has https://www.powerapps911.com/

As for the convert to .pdf element, again PowerApps &/or Microsoft Flow can do this for you. See https://www.youtube.com/watch?v=2rfAQe1kK8M