make_set, make_list

let Apps = datatable (User:string, AppName: string) [
 "User01", "1Password",
 "User01", "Camtasia 2021",
 "User02", "Camtasia 2021",
 "User03", "Microsoft Visio - en-us",
 "User03", "Microsoft Visio - en-us"
];
Apps
| summarize  make_set(AppName) by User

let Apps = datatable (User:string, AppName: string) [
 "User01", "1Password",
 "User01", "Camtasia 2021",
 "User02", "Camtasia 2021",
 "User03", "Microsoft Visio - en-us",
 "User03", "Microsoft Visio - en-us"
];
Apps
| summarize  make_list(AppName) by User

AppInventory_CL
| where TimeGenerated > ago (7d)
| summarize arg_max(TimeGenerated, *) by ManagedDeviceID_g, AppName_s
| summarize  InstalledApps = make_set(AppName_s) by ManagedDeviceID_g, ComputerName_s