PiP for Mac - Always on top window preview similar to the popular windows only OnTopReplica
TideTask - Control your procrastination and never miss a task again
Pennywise - Cross-platform application to open any website or media in a floating window
Motion Firefox - All-in-one time management tool in Firefox
Afloat - Create beautiful invoices in 3 clicks, without mistakes
Taskable - Using multiple work apps leads to tons of context switching, breaking flow and killing productivity.