I have now installed Updatest on two computers without problem.
On my MBA:
MacUpdater reports 120 apps
Updatest reports 116 apps
Latest reports 65 apps
On my Mini:
MacUpdater reports 51 apps
Updatest reports 63 apps
Latest reports 30 apps
I don’t understand why Updatest shows more than MacUpdater.
I shan’t bother with Latest anymore. Its only merit is being free, but Updatest is only $9.99 perpetual.