84 attachments in our database are flagged by the maker as suitable for sub-compact tractors, across 11 types: box blades (20), rear blades (15), landscape rakes (14), grapples (8), bale spears (6), post hole diggers (5), finish mowers (5), pallet forks (5), rotary tillers (4), one rotary cutter and one snow blower.
They weigh 65 to 510 lb, with a median of 292 lb. Of the 16 that list a PTO requirement, all need 10 to 15 PTO horsepower, so most of the list is non-powered implements.
Always check the hitch category and the implement's weight against your tractor's lift rating before you buy. The compatibility report on each tractor page does that check.