Always use the latest, release of the API. Some fixes to the handling of Conquest metadata are delivered via the API.
There are no known issues with versions 20.8 and 19.7.
There is an issue in version 1.0.6, where the Complete Action Form is not clearing the Stash Item created during its operation. When you Sign Out, you will be warned that there are unsaved, Stashed Changes relating to Action Completion. Provided that you have no other, truly unsaved work, you can ignore the warning.
If you have difficulty with using the Mobile App, please contact Conquest Support for assistance.