Outside of obvious form factor, and layout differences there are a few features that differ between the Sense phone/tablet app and the web app. Kudos to @jefflayman and @obscuredtrip for their suggestions and submissions. If you have more, please comment below and we can add.
In addition:
Some of these are layout differences but worth noting.
-Some integrations Philips Hue, Wiser, Ecobee can only be set up and only appear in the mobile app under connected devices.
-DCM, generator, solar can only be set up using the mobile app but appear in the web app under connected devices.
-Goals only appear on the mobile app.
-Main Meter only displays $/hr on mobile.
-Devices show different amounts for Avg % of monthly use on web vs. mobile.
-Mobile app sorts devices by current wattage, web app is sorted alphabetically.
-Always on device list can be edited on mobile app but not web app.
-Web settings Electricity Info has it’s own tab, Mobile the option is behind the My Home tab.
-Mobile settings Connected Devices is it’s own tab. Web it’s behind the My Home tab.
-Web settings has a tab for Sense Monitor. Mobile it’s behind My Home tab.
-A data or factory reset can only be preformed using the mobile app.
-(bug) when display cost is enabled on the mobile app the web app dashboard displays the line on the graph incorrectly.