Qlik Sense Mobile for Client-Managed only works with Qlik Sense Enterprise on Windows. Yes, Qlik Sense Mobile supports "fully interactive online and offline analysis". Regarding the SaaS app:
QSM for SaaS is available for all editions of Qlik Sense on SaaS, including Qlik Sense Business. "QSM allows users to download applications to the device and open them even when there is no connection to the tenant. This is only possible when the Mobile download option is enabled for the tenant. Qlik Sense apps can be downloaded with all the available data or sliced using a bookmark as a filter. The downloaded apps will open offline depending on the device’s RAM capacity, as a local version of the Qlik Sense associative engine runs in the installed app and will require local resources to process and open the offline apps. Only one offline version of the same Qlik Sense app is available on QSM."
Reference: https://community.qlik.com/t5/Knowledge/Qlik-Sense-Mobile-for-SaaS-FAQ/ta-p/1805641
